Wise to use HDD as offline storage?

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

fj <jelenko@att.net> wrote:
> "cquirke (MVP Windows shell/user)" <cquirkenews@nospam.mvps.org>
> wrote in message news:v3luf192fl337ua69lb4t1l6sabm244623@4ax.com...
>> On Fri, 12 Aug 2005 20:17:56 +0100, Columbus <hiss@mail.com> wrote:
>>
>>> I'm a home PC user based in the UK. I run mainly office
>>> applications and downloading music. No gaming or power PC stuff.
>>
>>> (A) My music is mainly on two or three 160 GB drives. Much of that
>>> can be replaced.
>>
>>> (B) I have also got XP on a 15 GB system partition.
>>
>>> (C) Various downloaded programs, utilities and cache files take 45
>>> GB on another partition.
>>
>>> My drives are ATA 3.5inch internal drives. I find it easy enough to
>>> put them in or take them out of the PC cabinet without needing to
>>> get an expensive USB attached hard drive.
>>
>>> I want to keep backup copies of the partitions used by the system (B
>>> above) and downloaded programs (C above).
>>
>>> How viable is it for a user like me to use a HARD DRIVE (maybe 160
>>> GB or 200 GB) as a backup medium?
>>
>> Caveats:
>>
>> 1) XP original (SP0) can't "see" HDs < 137G
>> 2) XP installations do not survive file-level copying, must image
>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

> So, means you should remove the power cord before removing hard drives?

He's just plain wrong and yes, you can remove the power cord.

>> 4) S-ATA hot-swappability requires S-ATA power connection
>> 5) Single recent backup may contain pre-existing problems

> Right. This 'simply' implies that you need to do a complete system
> backup just after installing Windows and setting up your default
> applications. Then, keep this known good backup separate from the
> on-going/periodic backups, which can be used if you need to restore
> from hardware failure.

Its better to have more than one backup of the full system.
Then if the system does get molested by a preexisting problem
you can step back to the older backup if you need to.

The main advantage of that approach over the backup taken just
after the clean install is that you're likely to have configured stuff
over time since the clean install and those config changes will be
lost if you go back to the backup done just after the clean install.

>> 6) HDs don't sem to like brackets and exclosures

> You're referring to heat - yes?

Cant see what he's on about with 'brackets' unless he is
referring to some drives like the Barracudas that get rid
of heat by conduction to the metal drive bay stack and can get
quite hot if you use plastic rails etc that stop that happening.

> I.e., the temperature of HDD's in external enclosures run hotter than when
> installed in a professionally built PC?

> How about the external enclosures with built in fans? [The ones that actually
> have ventilation for moving new air in, hot air out]

They're not usually as well done as the main system case airflow wise.

> Lastly, how about 2.5" harddrives? I've got one running in an
> aluminum case made by IWILL. It runs cooler to the touch than the
> bottom of my notebook where the hard drive is located. Are 2.5"
> HDD's any more susceptible to heat induced errors than 3.5" ones?

Nope, if anything less susceptible. They still dont like it tho, the Dell
laptops/notebooks that tend to run the drives right at the max the
drive manufacturer allows are notoriously for being hard drive killers.

>> So yes; you could use (say) BING from www.bootitng.com to image off
>> C: to another HD, as long as you unplug the PC from mains before
>> connecting and disconnecting the extra HD. Bear in mind the risk of
>> including problems within the backup, e.g. (say) a malware that
>> infected the system 29 days ago that has a 30-day payload fuse.
>>
>> For the rest of the data, I'd do file-level copies rather than image
>> backups, so that the backups are browsable. For the same reason, I'd
>> keep data you wanted to browse, off the C: that you will image.
>>
>> If copying files to CDR or DVDR, bear in mind that different file
>> system rules can knock file and path names around, attributes could
>> revert to read-only, and NTFS-specific metadata will typically be
>> lost. To preserve those things, consider first archiving within a
>> .zip (using something that manages the NTFS fluff, if that's
>> important to you) and then drop those .zip onto the CDR or DVDR.

 

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
> Eric Gisin wrote
>> fj <jelenko@att.net> wrote
>>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote

>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>> Nonsense. All the Molex are powered off.

>> The IDE ports are disabled. Only PS/2, USB, PCI, perhaps RAM are on.
>> Even disabling IDE channel in Device Manager allows hot swap.

> That's an interesting assertion.

Its not an assertion, its a fact.

> I can meter molex power leads to test those,

And that is all you need to do.

> but checking the data cables would be more difficult.

Nope, you can do that with the same multimeter.
At a spare connector on a ribbon cable or the
motherboard end with the ribbon cable unplugged.

> Given the risks involved,

There are no risks involved.

> I'd like a couple of URLs on that?

Your problem. It should be obvious from what needs
to be powered with an ATX system so that it can be
turned on from the keyboard or wake on lan etc.

 

[Guest]

Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

I would think you would like to back up what you state with a few quality
url's as proof. Otherwise, you are blowing smoke.

--
Regards,

Richard Urban
Microsoft MVP Windows Shell/User

Quote from: George Ankner
"If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!"

"Rod Speed" <rod_speed@yahoo.com> wrote in message
news:3ma2bsF15u87jU1@individual.net...
> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
>> Eric Gisin wrote
>>> fj <jelenko@att.net> wrote
>>>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
>
>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>
>>> Nonsense. All the Molex are powered off.
>
>>> The IDE ports are disabled. Only PS/2, USB, PCI, perhaps RAM are on.
>>> Even disabling IDE channel in Device Manager allows hot swap.
>
>> That's an interesting assertion.
>
> Its not an assertion, its a fact.
>
>> I can meter molex power leads to test those,
>
> And that is all you need to do.
>
>> but checking the data cables would be more difficult.
>
> Nope, you can do that with the same multimeter.
> At a spare connector on a ribbon cable or the
> motherboard end with the ribbon cable unplugged.
>
>> Given the risks involved,
>
> There are no risks involved.
>
>> I'd like a couple of URLs on that?
>
> Your problem. It should be obvious from what needs
> to be powered with an ATX system so that it can be
> turned on from the keyboard or wake on lan etc.
>
>
>

 

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
> Rod Speed <rod_speed@yahoo.com> wrote
>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
>>> Columbus <hiss@mail.com> wrote

>>>> How viable is it for a user like me to use a HARD DRIVE
>>>> (maybe 160 GB or 200 GB) as a backup medium?

>>> Caveats:

>>> 1) XP original (SP0) can't "see" HDs < 137G

>> You've got that backwards. And they can see drives > 137G,
>> they'll just corrupt the data as access wraps at that point.

> Yes indeed; the < should be a >

> It would be a lot safer if XP SP0 would simply refuse
> to "see" an over-137G than appear to work and then
> barf the data, so I if anything, your assertion

It isnt an assertion, its a fact.

> re-inforces my caveat, unless partitioning keeps
> the volumes that are used, short of that point.

I chose to comment on your claim that the original XP
cant 'see' drives over 137G. That is just plain wrong.

>>> 2) XP installations do not survive file-level copying, must image

>> Wrong. Have fun explaining xxclone.

> I haven't used XXClone, but I've certainly seen what happens
> when methods that work flawlessly with Win9x installations
> are applied to XP installations. The result doesn't boot,
> even if you get all the boot code stuff spot on.

Irrelevant to your assertion that file level copying isnt possible.

That is just plain wrong. Most of the cloners do it that way.
Essentially because they are mostly used when upgrading
the boot drive to a bigger one and file copying is the most
convenient way to do that.

>> And you dont need a bootable copy for backup anyway.

> Depends why you are trying to backup, doesn't it?

Nope.

> Someone backing up the whole of C: is
> liable to expect a restore to be bootable.

The restore being bootable is an entirely separate
question to whether the backup itself is bootable.

>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>> Wrong. And the worst you have to do is unplug
>> the power supply from the mains anyway.

> I'd remove the mains; that's what I'm saying.

No need.

> ATX "off" definately maintains a
> standby trickle of power to the system;

Yes.

> what may be debatable is whether this power goes
> to the HDs, via power leads or via the data connections.

No its not debateable, its trivial to measure and prove it doesnt happen.

>>> 4) S-ATA hot-swappability requires S-ATA power connection
>>> 5) Single recent backup may contain pre-existing problems
>>> 6) HDs don't sem to like brackets and exclosures

>> Bullshit.

> Speaking from experience, my friend.

No you arent, you're actually grossly misusing the term 'brackets'

> I see far more dead HDs from brackets than I do from
> "normal" use; why that is, is open to conjecture,

Nope, its completely trivial to seen what is different between
an external enclosure and a drive mounted internally.

> but that's the mileage.

No it isnt with 'brackets'

> Or are you claiming it's "bullshit" that a malware can
> permeate a system, and backups thereof, before
> hatching a destructive payload several days later?

Nope, that comment applied to just your last line, 6)

> Or are you disputing Western Digital's advice NOT to hot-swap their
> S-ATA drives if using the legacy power connectors they provide?

Nope, that comment applied to just your last line, 6)

>>> For the rest of the data, I'd do file-level copies rather
>>> than image backups, so that the backups are browsable.

>> Any decent imager allows you to browse the image.

> OK, so don't use any of the indecent ones that abound.

The vast bulk of the mainstream imagers allow you to browse the image.

 

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
> Rod Speed <rod_speed@yahoo.com> wrote
>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
>>> Columbus <hiss@mail.com> wrote

>>>> How viable is it for a user like me to use a HARD DRIVE
>>>> (maybe 160 GB or 200 GB) as a backup medium?

>>> Caveats:

>>> 1) XP original (SP0) can't "see" HDs < 137G

>> You've got that backwards. And they can see drives > 137G,
>> they'll just corrupt the data as access wraps at that point.

> Yes indeed; the < should be a >

> It would be a lot safer if XP SP0 would simply refuse
> to "see" an over-137G than appear to work and then
> barf the data, so I if anything, your assertion

It isnt an assertion, its a fact.

> re-inforces my caveat, unless partitioning keeps
> the volumes that are used, short of that point.

I chose to comment on your claim that the original XP
cant 'see' drives over 137G. That is just plain wrong.

>>> 2) XP installations do not survive file-level copying, must image

>> Wrong. Have fun explaining xxclone.

> I haven't used XXClone, but I've certainly seen what happens
> when methods that work flawlessly with Win9x installations
> are applied to XP installations. The result doesn't boot,
> even if you get all the boot code stuff spot on.

Irrelevant to your assertion that file level copying isnt possible.

That is just plain wrong. Most of the cloners do it that way.
Essentially because they are mostly used when upgrading
the boot drive to a bigger one and file copying is the most
convenient way to do that.

>> And you dont need a bootable copy for backup anyway.

> Depends why you are trying to backup, doesn't it?

Nope.

> Someone backing up the whole of C: is
> liable to expect a restore to be bootable.

The restore being bootable is an entirely separate
question to whether the backup itself is bootable.

>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>> Wrong. And the worst you have to do is unplug
>> the power supply from the mains anyway.

> I'd remove the mains; that's what I'm saying.

No need.

> ATX "off" definately maintains a
> standby trickle of power to the system;

Yes.

> what may be debatable is whether this power goes
> to the HDs, via power leads or via the data connections.

No its not debateable, its trivial to measure and prove it doesnt happen.

>>> 4) S-ATA hot-swappability requires S-ATA power connection
>>> 5) Single recent backup may contain pre-existing problems
>>> 6) HDs don't sem to like brackets and exclosures

>> Bullshit.

> Speaking from experience, my friend.

No you arent, you're actually grossly misusing the term 'brackets'

> I see far more dead HDs from brackets than I do from
> "normal" use; why that is, is open to conjecture,

Nope, its completely trivial to seen what is different between
an external enclosure and a drive mounted internally.

> but that's the mileage.

No it isnt with 'brackets'

> Or are you claiming it's "bullshit" that a malware can
> permeate a system, and backups thereof, before
> hatching a destructive payload several days later?

Nope, that comment applied to just your last line, 6)

> Or are you disputing Western Digital's advice NOT to hot-swap their
> S-ATA drives if using the legacy power connectors they provide?

Nope, that comment applied to just your last line, 6)

>>> For the rest of the data, I'd do file-level copies rather
>>> than image backups, so that the backups are browsable.

>> Any decent imager allows you to browse the image.

> OK, so don't use any of the indecent ones that abound.

The vast bulk of the mainstream imagers allow you to browse the image.

 

[GE]

Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:

>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>
>>Wrong. And the worst you have to do is unplug
>>the power supply from the mains anyway.
>
> I'd remove the mains; that's what I'm saying. ATX "off" definately
> maintains a standby trickle of power to the system;

No, not really. No digital system works with a "trickle of power". It's
either enough power to supply what's connected to it properly, or it isn't.
If it isn't, the power supply is not adequate for the system, and the
system may function partially, but won't function properly. I guess we can
assume that we are talking about a PC that does function properly.

(There is actually a term "trickle supply", but that's more for battery
chargers and similar circuits; it usually refers to the small current
that's necessary to keep a charged battery fully charged. The ATX standby
supply is not what's commonly called a "trickle supply"; it is a full-blown
+5 V supply that supplies at least 1 A for standby power -- just as its
name says.)


The ATX standby power is only provided on the ATX standby power line
(called +5VSB); all other power lines are "off" in standby mode. There's no
"trickle of power": the +5VSB line is fully on, all others are fully off.

What is in fact connected to the +5VSB (ATX standby power) is dependent on
the specific mobo and the BIOS configuration, of course, but with the ATX
standard guaranteeing no more than 1 A on that line, and it being only +5 V
(no +12 V standby power), I doubt there are any decent mobos out there that
supply their IDE controllers with standby power. If they did, that would be
a serious design flaw, given that the harddisk that's connected to that
connector in any case is not supplied with power during standby (because
the standard harddisk power connector doesn't carry the +5VSB standby power
line).

While it is theoretically thinkable that a ill-designed mobo supplies its
IDE controlles from ATX standby power, it is still not clear whether this
does any harm to the harddisk. If it does, it probably does so whether or
not you disconnect the harddisk while power is supplied to its IDE
interface -- the damage being done by it being connected, not by the act of
connecting or disconnecting it.

Since there have been questions about "serious links" here... how about
some serious links confirming that there are indeed mobos that do supply
their IDE controllers with standby power (which I doubt)? Or links about
how harddisk controllers deal with their IDE interface being powered while
their own power supply is off (probably a situation deemed out of specs by
the drive manufacturer, therefore any mobo that would do that is not
adequate anyway)? Regarding links to back up what I said... that's all just
explaining the ATX standard. You should be able to find any number of links
to information about this.


OTOH, telling a newbie to disconnect the power cord before opening the PC
case can be good advice. But not because of "power trickles" in the
computer... This good advice should come with an equally good explanation,
like "As long as you're not knowing what you're doing, it's a good idea to
always disconnect the power cord of /anything/ you open."

Gerhard

 

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Ge wrote:

> On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:
>
>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>>
>>>Wrong. And the worst you have to do is unplug
>>>the power supply from the mains anyway.
>>
>> I'd remove the mains; that's what I'm saying. ATX "off" definately
>> maintains a standby trickle of power to the system;
>
> No, not really. No digital system works with a "trickle of power". It's
> either enough power to supply what's connected to it properly, or it
> isn't. If it isn't, the power supply is not adequate for the system, and
> the system may function partially, but won't function properly. I guess we
> can assume that we are talking about a PC that does function properly.
>
> (There is actually a term "trickle supply", but that's more for battery
> chargers and similar circuits; it usually refers to the small current
> that's necessary to keep a charged battery fully charged. The ATX standby
> supply is not what's commonly called a "trickle supply"; it is a
> full-blown +5 V supply that supplies at least 1 A for standby power --
> just as its name says.)
>
>
> The ATX standby power is only provided on the ATX standby power line
> (called +5VSB); all other power lines are "off" in standby mode. There's
> no "trickle of power": the +5VSB line is fully on, all others are fully
> off.
>
> What is in fact connected to the +5VSB (ATX standby power) is dependent on
> the specific mobo and the BIOS configuration, of course, but with the ATX
> standard guaranteeing no more than 1 A on that line, and it being only +5
> V (no +12 V standby power), I doubt there are any decent mobos out there
> that supply their IDE controllers with standby power. If they did, that
> would be a serious design flaw, given that the harddisk that's connected
> to that connector in any case is not supplied with power during standby
> (because the standard harddisk power connector doesn't carry the +5VSB
> standby power line).
>
> While it is theoretically thinkable that a ill-designed mobo supplies its
> IDE controlles from ATX standby power, it is still not clear whether this
> does any harm to the harddisk. If it does, it probably does so whether or
> not you disconnect the harddisk while power is supplied to its IDE
> interface -- the damage being done by it being connected, not by the act
> of connecting or disconnecting it.
>
> Since there have been questions about "serious links" here... how about
> some serious links confirming that there are indeed mobos that do supply
> their IDE controllers with standby power (which I doubt)? Or links about
> how harddisk controllers deal with their IDE interface being powered while
> their own power supply is off (probably a situation deemed out of specs by
> the drive manufacturer, therefore any mobo that would do that is not
> adequate anyway)? Regarding links to back up what I said... that's all
> just explaining the ATX standard. You should be able to find any number of
> links to information about this.
>
>
> OTOH, telling a newbie to disconnect the power cord before opening the PC
> case can be good advice. But not because of "power trickles" in the
> computer... This good advice should come with an equally good explanation,
> like "As long as you're not knowing what you're doing, it's a good idea to
> always disconnect the power cord of /anything/ you open."

You're being pedantic here IMO. +5VSB is a "trickle" compared to the normal
operating power. It seems a pointless argument that you are raising.

The point is that there is power in the case and on the motherboard with the
ATX power in the "off" state. And depending on what you're doing that
standby power can become full power very easily and very quickly--I've
inserted boards into or removed boards from a machine and had it power up
while I was doing it (and don't tell me it can't happen based on some
fancy-Dan analytical model--in the real world it can and does), sometimes
to the detriment of one component or another.

When adding or removing hardware, the best policy is a cold chassis, that
means either unplugged or hard-off.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

 

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

Richard Urban [MVP] <richardurbanREMOVETHIS@hotmail.com> wrote

> I would think

Not a shred of evidence that you are actually capable of thought.

You clearly couldnt bullshit your way out of a wet paper
bag even if your pathetic excuse for a 'life' depended on it.

> you would like to back up what you state with a few quality url's as proof.

Dont need any of those with a question as basic as the one being discussed.
Even someone as stupid as you should be able to check whether hard drives
are powered up when an ATX system is shutdown, using such simple approachs
as checking if there is any power on the molex connector and it only requires
a multimeter and something viable between your ears to check the data cable.

> Otherwise, you are blowing smoke.

See above on the wet paper bag.


> Rod Speed <rod_speed@yahoo.com> wrote
>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
>>> Eric Gisin wrote
>>>> fj <jelenko@att.net> wrote
>>>>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org>
>>>>> wrote

>>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>>>> Nonsense. All the Molex are powered off.

>>>> The IDE ports are disabled. Only PS/2, USB, PCI, perhaps RAM are
>>>> on. Even disabling IDE channel in Device Manager allows hot swap.

>>> That's an interesting assertion.

>> Its not an assertion, its a fact.

>>> I can meter molex power leads to test those,

>> And that is all you need to do.

>>> but checking the data cables would be more difficult.

>> Nope, you can do that with the same multimeter.
>> At a spare connector on a ribbon cable or the
>> motherboard end with the ribbon cable unplugged.

>>> Given the risks involved,

>> There are no risks involved.

>>> I'd like a couple of URLs on that?

>> Your problem. It should be obvious from what needs
>> to be powered with an ATX system so that it can be
>> turned on from the keyboard or wake on lan etc.

 

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Archived from groups: alt.video.dvd.tech,microsoft.public.windowsxp.hardware,comp.sys.ibm.pc.hardware.storage (More info?)

On Mon, 15 Aug 2005 09:27:54 +1000, "Rod Speed"
>cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org>
>> Eric Gisin wrote
>>> fj <jelenko@att.net> wrote
>>>> cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote

>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>>> Nonsense. All the Molex are powered off.

>>> The IDE ports are disabled. Only PS/2, USB, PCI, perhaps RAM are on.
>>> Even disabling IDE channel in Device Manager allows hot swap.

>> That's an interesting assertion.

>Its not an assertion, its a fact.

It's not a fact because you say it is. Without proof, it's an
assertion, and one that I happen to be interested in.

But your attitude is making me less interested by the minute.

>> I can meter molex power leads to test those,

>And that is all you need to do.

Nope. More on that later.

>> but checking the data cables would be more difficult.

>Nope, you can do that with the same multimeter.
>At a spare connector on a ribbon cable or the
>motherboard end with the ribbon cable unplugged.

Quite a lot of combinations to test, even when you discount 40 of the
80 lines as common ground. Also, meters are fairly crude, when it
comes to transients - if a data line was to pulse once every 1/10th of
a second, it may not show up on a meter at all.

>> Given the risks involved,

>There are no risks involved.

Apart from crucial data on a costly hard drive, you mean?

>> I'd like a couple of URLs on that?

>Your problem. It should be obvious from what needs
>to be powered with an ATX system so that it can be
>turned on from the keyboard or wake on lan etc.

No, it's not my problem - I can simply discard your assertions as
unsubstantiated and move on, if you can't back them up. As long as
there's a risk of power being applied to devices while "switched off",
I'll advise not plugging them in or out unless you are certain it's
safe to do so. You may have that certainty; I do not.



>------------------------ ---- --- -- - - - -
Forget http://cquirke.blogspot.com and check out a
better one at http://topicdrift.blogspot.com instead!
>------------------------ ---- --- -- - - - -

 

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On Mon, 15 Aug 2005 10:14:24 -0300, Ge <gefiedler@globo.com> wrote:
>On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:

>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>>>Wrong. And the worst you have to do is unplug
>>>the power supply from the mains anyway.

>> I'd remove the mains; that's what I'm saying. ATX "off" definately
>> maintains a standby trickle of power to the system;

>No, not really. No digital system works with a "trickle of power". It's
>either enough power to supply what's connected to it properly, or it isn't.

I was referring to the standby power line that you mention a bit
further on. On that line, it's a regular 5V; when looking at the
total current draw from the PSU, it appears as a "trickle" there.

Still, enough to get into trouble. I saw a particular line of power
supplies that would tend to heat up when ATX "off" (the top of the
case would be warmer than when the PC was running), and sometimes
these would go Bang! and blow a cap when switched on.

This would then spike the +12V and typically kill motherboard, RAM,
HD, and the CD-ROM would often fail a week or so later.

One possible mechanism for this failure pattern might be that the
lower standby current with no fan caused the PSU to "run" hotter than
normal operations with the fan running. Then when the initial demands
of full power are applied to this heated circuitry, pop!

Or it could be some other mechanism entirely, unrelated to the warmer
temperature noted when "just" supplying standby power.

>The ATX standby power is only provided on the ATX standby power line
>(called +5VSB); all other power lines are "off" in standby mode. There's no
>"trickle of power": the +5VSB line is fully on, all others are fully off.

So what we need to know is where that line goes., and whether power
from that line emerges through other ciruitry as data line activity.

>What is in fact connected to the +5VSB (ATX standby power) is dependent on
>the specific mobo and the BIOS configuration, of course, but with the ATX
>standard guaranteeing no more than 1 A on that line, and it being only +5 V
>(no +12 V standby power), I doubt there are any decent mobos out there that
>supply their IDE controllers with standby power. If they did, that would be
>a serious design flaw, given that the harddisk that's connected to that
>connector in any case is not supplied with power during standby (because
>the standard harddisk power connector doesn't carry the +5VSB standby power
>line).

Well, it could be some sort of "ghost power" arrangement I suppose,
much as some USBs which have external power connections "don't need
external power" and can run without it.

I notice some mobos support wake-up from various IRQs, including the
IDE controllers (wake-on-demand is not a not a feature I use, so I
don't spend much time in that part of CMOS setup). If the mobo can
sense events on the IDE, then that suggests power on the IDE.

>While it is theoretically thinkable that a ill-designed mobo supplies its
>IDE controlles from ATX standby power, it is still not clear whether this
>does any harm to the harddisk. If it does, it probably does so whether or
>not you disconnect the harddisk while power is supplied to its IDE
>interface -- the damage being done by it being connected, not by the act of
>connecting or disconnecting it.

Again, maybe and maybe not. It's quite possible to circuit something
that's safe for isolated power, i.e. a logic chip that derives power
from one of the IDE lines and doesn't rely on other HD components that
would have to formally powered via the molex.

>Since there have been questions about "serious links" here... how about
>some serious links confirming that there are indeed mobos that do supply
>their IDE controllers with standby power (which I doubt)? Or links about
>how harddisk controllers deal with their IDE interface being powered while
>their own power supply is off (probably a situation deemed out of specs by
>the drive manufacturer, therefore any mobo that would do that is not
>adequate anyway)? Regarding links to back up what I said... that's all just
>explaining the ATX standard. You should be able to find any number of links
>to information about this.

I don't have links, but I reckon if there's doubt on this, it's safer
not to assume it's safe to plug and unplug HDs while the ATX power is
connected but "switched off". We do know that while "off", power
enters the PC as a whole, and the mobo too; we are debating whether it
gets to the HDs. Until certain it's safe, I'd rather unplug the power

>OTOH, telling a newbie to disconnect the power cord before opening the PC
>case can be good advice. But not because of "power trickles" in the
>computer... This good advice should come with an equally good explanation,
>like "As long as you're not knowing what you're doing, it's a good idea to
>always disconnect the power cord of /anything/ you open."

Yep. In the old days of "real" power switches, there was a school of
thought that suggested it was safer for the PC's parts if mains was
plugged in but switched off, in that the system would still be
grounded via the earth line of the mains supply.

I'd say that's changed now, in the ATX era; if it ever was good
advice, it's less so these days.



>---------- ----- ---- --- -- - - - -
Proverbs Unscrolled #37
"Build it and they will come and break it"
>---------- ----- ---- --- -- - - - -

 

[tonyb]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke <jclarke.usenet@snet.net.invalid> wrote:
> Ge wrote:
>
>> On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:
>>
>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>>>
>>>> Wrong. And the worst you have to do is unplug
>>>> the power supply from the mains anyway.
>>>
>>> I'd remove the mains; that's what I'm saying. ATX "off" definately
>>> maintains a standby trickle of power to the system;
>>
>> No, not really. No digital system works with a "trickle of power".
>> It's either enough power to supply what's connected to it properly,
>> or it isn't. If it isn't, the power supply is not adequate for the
>> system, and the system may function partially, but won't function
>> properly. I guess we can assume that we are talking about a PC that
>> does function properly.
>>
>> (There is actually a term "trickle supply", but that's more for
>> battery chargers and similar circuits; it usually refers to the
>> small current that's necessary to keep a charged battery fully
>> charged. The ATX standby supply is not what's commonly called a
>> "trickle supply"; it is a full-blown +5 V supply that supplies at
>> least 1 A for standby power -- just as its name says.)
>>
>>
>> The ATX standby power is only provided on the ATX standby power line
>> (called +5VSB); all other power lines are "off" in standby mode.
>> There's no "trickle of power": the +5VSB line is fully on, all
>> others are fully off.
>>
>> What is in fact connected to the +5VSB (ATX standby power) is
>> dependent on the specific mobo and the BIOS configuration, of
>> course, but with the ATX standard guaranteeing no more than 1 A on
>> that line, and it being only +5 V (no +12 V standby power), I doubt
>> there are any decent mobos out there that supply their IDE
>> controllers with standby power. If they did, that would be a serious
>> design flaw, given that the harddisk that's connected to that
>> connector in any case is not supplied with power during standby
>> (because the standard harddisk power connector doesn't carry the
>> +5VSB standby power line).
>>
>> While it is theoretically thinkable that a ill-designed mobo
>> supplies its IDE controlles from ATX standby power, it is still not
>> clear whether this does any harm to the harddisk. If it does, it
>> probably does so whether or not you disconnect the harddisk while
>> power is supplied to its IDE interface -- the damage being done by
>> it being connected, not by the act of connecting or disconnecting it.
>>
>> Since there have been questions about "serious links" here... how
>> about some serious links confirming that there are indeed mobos that
>> do supply their IDE controllers with standby power (which I doubt)?
>> Or links about how harddisk controllers deal with their IDE
>> interface being powered while their own power supply is off
>> (probably a situation deemed out of specs by the drive manufacturer,
>> therefore any mobo that would do that is not adequate anyway)?
>> Regarding links to back up what I said... that's all just explaining
>> the ATX standard. You should be able to find any number of links to
>> information about this.
>>
>>
>> OTOH, telling a newbie to disconnect the power cord before opening
>> the PC case can be good advice. But not because of "power trickles"
>> in the computer... This good advice should come with an equally good
>> explanation, like "As long as you're not knowing what you're doing,
>> it's a good idea to always disconnect the power cord of /anything/
>> you open."

> You're being pedantic here IMO.

Nope.

> +5VSB is a "trickle" compared to the normal operating power.

YOU are being pedantic in fact.

> It seems a pointless argument that you are raising.

Corse it isnt when discussing whether its safe to unplug a hard
drive with an ATX system shutdown and the mains still connected.

> The point is that there is power in the case and on the motherboard
> with the ATX power in the "off" state. And depending on what you're
> doing that standby power can become full power very easily and very
> quickly--I've inserted boards into or removed boards from a machine
> and had it power up while I was doing it (and don't tell me it can't
> happen based on some fancy-Dan analytical model--in the real world it
> can and does),

How odd that its never happened to me once.

> sometimes to the detriment of one component or another.

> When adding or removing hardware, the best policy is
> a cold chassis, that means either unplugged or hard-off.

Not with just changing a hard drive it isnt. THAT is what was being discussed.

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

TonyB wrote:

> J. Clarke <jclarke.usenet@snet.net.invalid> wrote:
>> Ge wrote:
>>
>>> On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:
>>>
>>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>>>>
>>>>> Wrong. And the worst you have to do is unplug
>>>>> the power supply from the mains anyway.
>>>>
>>>> I'd remove the mains; that's what I'm saying. ATX "off" definately
>>>> maintains a standby trickle of power to the system;
>>>
>>> No, not really. No digital system works with a "trickle of power".
>>> It's either enough power to supply what's connected to it properly,
>>> or it isn't. If it isn't, the power supply is not adequate for the
>>> system, and the system may function partially, but won't function
>>> properly. I guess we can assume that we are talking about a PC that
>>> does function properly.
>>>
>>> (There is actually a term "trickle supply", but that's more for
>>> battery chargers and similar circuits; it usually refers to the
>>> small current that's necessary to keep a charged battery fully
>>> charged. The ATX standby supply is not what's commonly called a
>>> "trickle supply"; it is a full-blown +5 V supply that supplies at
>>> least 1 A for standby power -- just as its name says.)
>>>
>>>
>>> The ATX standby power is only provided on the ATX standby power line
>>> (called +5VSB); all other power lines are "off" in standby mode.
>>> There's no "trickle of power": the +5VSB line is fully on, all
>>> others are fully off.
>>>
>>> What is in fact connected to the +5VSB (ATX standby power) is
>>> dependent on the specific mobo and the BIOS configuration, of
>>> course, but with the ATX standard guaranteeing no more than 1 A on
>>> that line, and it being only +5 V (no +12 V standby power), I doubt
>>> there are any decent mobos out there that supply their IDE
>>> controllers with standby power. If they did, that would be a serious
>>> design flaw, given that the harddisk that's connected to that
>>> connector in any case is not supplied with power during standby
>>> (because the standard harddisk power connector doesn't carry the
>>> +5VSB standby power line).
>>>
>>> While it is theoretically thinkable that a ill-designed mobo
>>> supplies its IDE controlles from ATX standby power, it is still not
>>> clear whether this does any harm to the harddisk. If it does, it
>>> probably does so whether or not you disconnect the harddisk while
>>> power is supplied to its IDE interface -- the damage being done by
>>> it being connected, not by the act of connecting or disconnecting it.
>>>
>>> Since there have been questions about "serious links" here... how
>>> about some serious links confirming that there are indeed mobos that
>>> do supply their IDE controllers with standby power (which I doubt)?
>>> Or links about how harddisk controllers deal with their IDE
>>> interface being powered while their own power supply is off
>>> (probably a situation deemed out of specs by the drive manufacturer,
>>> therefore any mobo that would do that is not adequate anyway)?
>>> Regarding links to back up what I said... that's all just explaining
>>> the ATX standard. You should be able to find any number of links to
>>> information about this.
>>>
>>>
>>> OTOH, telling a newbie to disconnect the power cord before opening
>>> the PC case can be good advice. But not because of "power trickles"
>>> in the computer... This good advice should come with an equally good
>>> explanation, like "As long as you're not knowing what you're doing,
>>> it's a good idea to always disconnect the power cord of /anything/
>>> you open."
>
>> You're being pedantic here IMO.
>
> Nope.

Yep.

>> +5VSB is a "trickle" compared to the normal operating power.
>
> YOU are being pedantic in fact.

How so? I'm not the one quibbling over the definition of "trickle".

>> It seems a pointless argument that you are raising.
>
> Corse it isnt when discussing whether its safe to unplug a hard
> drive with an ATX system shutdown and the mains still connected.

It is pointless to argue whether the power is "a trickle" or "full current
on the +5VSB". You are welcome to think that is it a matter of great
importance to argue that point. If you do however, eventually everyone
will become bored with that subject and stop paying attention to anything
you post.

>> The point is that there is power in the case and on the motherboard
>> with the ATX power in the "off" state. And depending on what you're
>> doing that standby power can become full power very easily and very
>> quickly--I've inserted boards into or removed boards from a machine
>> and had it power up while I was doing it (and don't tell me it can't
>> happen based on some fancy-Dan analytical model--in the real world it
>> can and does),
>
> How odd that its never happened to me once.

Don't worry, if you continue to swap components around with the machine in
ATX off it will eventually. Probably at the least opportune time.

>> sometimes to the detriment of one component or another.
>
>> When adding or removing hardware, the best policy is
>> a cold chassis, that means either unplugged or hard-off.
>
> Not with just changing a hard drive it isnt. THAT is what was being
> discussed.

With _anything_ that is not specifically documented to be hot-swappable.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

cquirke (MVP Windows shell/user) <cquirkenews@nospam.mvps.org> wrote
> Ge <gefiedler@globo.com> wrote
>> cquirke (MVP Windows shell/user) wrote

>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs

>>>> Wrong. And the worst you have to do is unplug
>>>> the power supply from the mains anyway.

>>> I'd remove the mains; that's what I'm saying. ATX "off" definately
>>> maintains a standby trickle of power to the system;

>> No, not really. No digital system works with a "trickle of power".
>> It's either enough power to supply what's connected to it properly,
>> or it isn't.

> I was referring to the standby power line that you mention a bit
> further on. On that line, it's a regular 5V; when looking at the
> total current draw from the PSU, it appears as a "trickle" there.

> Still, enough to get into trouble.

Not with the unplugging of hard drives it isnt.

> I saw a particular line of power supplies that would tend
> to heat up when ATX "off" (the top of the case would be
> warmer than when the PC was running), and sometimes
> these would go Bang! and blow a cap when switched on.

One completely dud power supply design is completely
irrelevant to what is being discussed, whether hard drives
are powered from the +5VSB, they arent, even indirectly.

> This would then spike the +12V and typically kill motherboard,
> RAM, HD, and the CD-ROM would often fail a week or so later.

> One possible mechanism for this failure pattern might be that the
> lower standby current with no fan caused the PSU to "run" hotter
> than normal operations with the fan running. Then when the initial
> demands of full power are applied to this heated circuitry, pop!

How odd that normal ATX power supplys
dont even get warm in standby mode.

> Or it could be some other mechanism entirely, unrelated to the
> warmer temperature noted when "just" supplying standby power.

Yep, most do fail on power on.

>> The ATX standby power is only provided on the ATX
>> standby power line (called +5VSB); all other power lines
>> are "off" in standby mode. There's no "trickle of power":
>> the +5VSB line is fully on, all others are fully off.

> So what we need to know is where that line goes.,

Its obvious where that goes, to components that need to
be powered in standby mode. Thats the whole point of it.

And you can check that trivially with the
keyboard and mouse with optical mice.

> and whether power from that line emerges
> through other ciruitry as data line activity.

Corse it doesnt, there is no 'data line activity' in standby mode.

And its completely trivial to check that with a multimeter.

>> What is in fact connected to the +5VSB (ATX standby power)
>> is dependent on the specific mobo and the BIOS configuration,
>> of course, but with the ATX standard guaranteeing no more than
>> 1 A on that line, and it being only +5 V (no +12 V standby power),
>> I doubt there are any decent mobos out there that supply their
>> IDE controllers with standby power. If they did, that would be
>> a serious design flaw, given that the harddisk that's connected
>> to that connector in any case is not supplied with power during
>> standby (because the standard harddisk power connector
>> doesn't carry the +5VSB standby power line).

> Well, it could be some sort of "ghost power" arrangement I suppose,

Nope.

> much as some USBs which have external power connections
> "don't need external power" and can run without it.

Different situation entirely. The USB standard allows for USB
devices to be powered from the USB cable if they dont use
too much power. No 'ghost power' involved whatever.

> I notice some mobos support wake-up from various IRQs,

Yes.

> including the IDE controllers

Nope.

> (wake-on-demand is not a not a feature I use, so I
> don't spend much time in that part of CMOS setup).

And clearly know nothing about it.

+5VSB doesnt even make it to the ribbon cable.

> If the mobo can sense events on the IDE,

It cant, and there are no 'events' in that sense.

> then that suggests power on the IDE.

Fanciful, and its completely trivial to use a multimeter
and prove that there is no power on the IDE in standby.

>> While it is theoretically thinkable that a ill-designed mobo
>> supplies its IDE controlles from ATX standby power, it is still not
>> clear whether this does any harm to the harddisk. If it does, it
>> probably does so whether or not you disconnect the harddisk while
>> power is supplied to its IDE interface -- the damage being done by
>> it being connected, not by the act of connecting or disconnecting it.

> Again, maybe and maybe not. It's quite possible to circuit something
> that's safe for isolated power, i.e. a logic chip that derives power
> from one of the IDE lines and doesn't rely on other HD components
> that would have to formally powered via the molex.

Waffle.

>> Since there have been questions about "serious links" here... how
>> about some serious links confirming that there are indeed mobos that
>> do supply their IDE controllers with standby power (which I doubt)?
>> Or links about how harddisk controllers deal with their IDE
>> interface being powered while their own power supply is off
>> (probably a situation deemed out of specs by the drive manufacturer,
>> therefore any mobo that would do that is not adequate anyway)?
>> Regarding links to back up what I said... that's all just explaining
>> the ATX standard. You should be able to find any number of links to
>> information about this.

> I don't have links, but I reckon if there's doubt on this,

There isnt, and its completely trivial to eliminate all doubt with a multimeter.

> it's safer not to assume it's safe to plug and unplug
> HDs while the ATX power is connected but "switched off".

Its safer to wear a seat belt and superglue your sox
on and wear a hazmat suit too. Most of us dont bother.

You're welcome to do whatever you want.

You arent welcome to advise others to do what you are stupid enough to do.

> We do know that while "off", power enters the PC as a whole,
> and the mobo too; we are debating whether it gets to the HDs.

And its completely trivial to prove that it doesnt.

> Until certain it's safe, I'd rather unplug the power

Your problem.

>> OTOH, telling a newbie to disconnect the power cord before opening
>> the PC case can be good advice. But not because of "power trickles"
>> in the computer... This good advice should come with an equally good
>> explanation, like "As long as you're not knowing what you're doing, it's
> a good idea to always disconnect the power cord of /anything/ you open."

> Yep. In the old days of "real" power switches, there was
> a school of thought that suggested it was safer for the PC's
> parts if mains was plugged in but switched off, in that the system
> would still be grounded via the earth line of the mains supply.

Its still true. Static damage is the only
possibility when unplugging the hard drive.

> I'd say that's changed now, in the ATX era;

You're wrong.

> if it ever was good advice,

Corse it was, and is.

> it's less so these days.

Wrong again.

Even when plugging and unplugging PCI cards, which is certainly
undesirable with the system in standby mode, its better to turn
the mains off at the switch near the mains cord connector than
to unplug the mains cord, so the system is still grounded.

 

[tonyb]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke <jclarke.usenet@snet.net.invalid> wrote:
> TonyB wrote:
>
>> J. Clarke <jclarke.usenet@snet.net.invalid> wrote:
>>> Ge wrote:
>>>
>>>> On 8/14/05 19:43:29, cquirke (MVP Windows shell/user) wrote:
>>>>
>>>>>>> 3) ATX "off" maintains power trickle; unsafe to remove IDE HDs
>>>>>
>>>>>> Wrong. And the worst you have to do is unplug
>>>>>> the power supply from the mains anyway.
>>>>>
>>>>> I'd remove the mains; that's what I'm saying. ATX "off"
>>>>> definately maintains a standby trickle of power to the system;
>>>>
>>>> No, not really. No digital system works with a "trickle of power".
>>>> It's either enough power to supply what's connected to it properly,
>>>> or it isn't. If it isn't, the power supply is not adequate for the
>>>> system, and the system may function partially, but won't function
>>>> properly. I guess we can assume that we are talking about a PC that
>>>> does function properly.
>>>>
>>>> (There is actually a term "trickle supply", but that's more for
>>>> battery chargers and similar circuits; it usually refers to the
>>>> small current that's necessary to keep a charged battery fully
>>>> charged. The ATX standby supply is not what's commonly called a
>>>> "trickle supply"; it is a full-blown +5 V supply that supplies at
>>>> least 1 A for standby power -- just as its name says.)
>>>>
>>>>
>>>> The ATX standby power is only provided on the ATX standby power
>>>> line (called +5VSB); all other power lines are "off" in standby
>>>> mode. There's no "trickle of power": the +5VSB line is fully on,
>>>> all others are fully off.
>>>>
>>>> What is in fact connected to the +5VSB (ATX standby power) is
>>>> dependent on the specific mobo and the BIOS configuration, of
>>>> course, but with the ATX standard guaranteeing no more than 1 A on
>>>> that line, and it being only +5 V (no +12 V standby power), I doubt
>>>> there are any decent mobos out there that supply their IDE
>>>> controllers with standby power. If they did, that would be a
>>>> serious design flaw, given that the harddisk that's connected to
>>>> that connector in any case is not supplied with power during
>>>> standby (because the standard harddisk power connector doesn't
>>>> carry the +5VSB standby power line).
>>>>
>>>> While it is theoretically thinkable that a ill-designed mobo
>>>> supplies its IDE controlles from ATX standby power, it is still not
>>>> clear whether this does any harm to the harddisk. If it does, it
>>>> probably does so whether or not you disconnect the harddisk while
>>>> power is supplied to its IDE interface -- the damage being done by
>>>> it being connected, not by the act of connecting or disconnecting
>>>> it.
>>>>
>>>> Since there have been questions about "serious links" here... how
>>>> about some serious links confirming that there are indeed mobos
>>>> that do supply their IDE controllers with standby power (which I
>>>> doubt)? Or links about how harddisk controllers deal with their IDE
>>>> interface being powered while their own power supply is off
>>>> (probably a situation deemed out of specs by the drive
>>>> manufacturer, therefore any mobo that would do that is not
>>>> adequate anyway)? Regarding links to back up what I said... that's
>>>> all just explaining the ATX standard. You should be able to find
>>>> any number of links to information about this.
>>>>
>>>>
>>>> OTOH, telling a newbie to disconnect the power cord before opening
>>>> the PC case can be good advice. But not because of "power trickles"
>>>> in the computer... This good advice should come with an equally
>>>> good explanation, like "As long as you're not knowing what you're
>>>> doing, it's a good idea to always disconnect the power cord of
>>>> /anything/ you open."
>>
>>> You're being pedantic here IMO.
>>
>> Nope.

> Yep.

Nope.

>>> +5VSB is a "trickle" compared to the normal operating power.

>> YOU are being pedantic in fact.

> How so?

You're the one splitting hairs on the use of the word trickle.

> I'm not the one quibbling over the definition of "trickle".

All that means is that you arent the only one being pedantic.

>>> It seems a pointless argument that you are raising.

>> Corse it isnt when discussing whether its safe to unplug a hard
>> drive with an ATX system shutdown and the mains still connected.

> It is pointless to argue whether the power
> is "a trickle" or "full current on the +5VSB".

And you did that yourself in spades.

> You are welcome to think that is it a matter
> of great importance to argue that point.

Never even said anything about 'a matter of great
importance' just said that it isnt a pointless argument.

> If you do however, eventually everyone will become bored
> with that subject and stop paying attention to anything you post.

Anyone is always welcome to be selective about what they choose to read.

>>> The point is that there is power in the case and on the motherboard
>>> with the ATX power in the "off" state. And depending on what you're
>>> doing that standby power can become full power very easily and very
>>> quickly--I've inserted boards into or removed boards from a machine
>>> and had it power up while I was doing it (and don't tell me it can't
>>> happen based on some fancy-Dan analytical model--in the real world
>>> it can and does),

>> How odd that its never happened to me once.

> Don't worry, if you continue to swap components
> around with the machine in ATX off it will eventually.

I've likely done it a lot more than you have thanks.

I have enough of a clue to realise when the mains needs to be unplugged
and when it doesnt. It doesnt when unplugging or plugging hard drives.

> Probably at the least opportune time.

Never ever happens to be, because I understand when
the mains needs to be disconnected and when it doesnt.

>>> sometimes to the detriment of one component or another.

>>> When adding or removing hardware, the best policy is
>>> a cold chassis, that means either unplugged or hard-off.

>> Not with just changing a hard drive it isnt.
>> THAT is what was being discussed.

> With _anything_ that is not specifically documented to be hot-swappable.

Wrong again. I know that the hard drives arent powered in standby mode thanks.

I also know that the PCI cards and ram are.

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/15/05 13:11:23, Arno Wagner wrote:

>> While it is theoretically thinkable that a ill-designed mobo supplies its
>> IDE controlles from ATX standby power, it is still not clear whether this
>> does any harm to the harddisk. If it does, it probably does so whether or
>> not you disconnect the harddisk while power is supplied to its IDE
>> interface -- the damage being done by it being connected, not by the act of
>> connecting or disconnecting it.

> To sum up: Connecting or disconnectin HDD power when voltages are
> present is extremely risky ...

No contest here. But the question was whether there are any voltages
present at the harddisk with the ATX power supply in standby mode -- which
you confirm that there aren't any.

> Since this would be complete nonsense, I doubt there is any link.
> Why spend the extra money to give the controller a power-switch
> that switches the controller over between +5VSB and +5V, when the
> controller is perfectly happy to work on +V5?

Exactly...

> Actually it is good advice because +5VSB does go to some devices like
> the PCI cards.

I wouldn't advise exchanging cards while on standby power. But the question
was about exchanging drives while on standby.

Gerhard

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/15/05 12:37:26, cquirke (MVP Windows shell/user) wrote:

> I was referring to the standby power line that you mention a bit
> further on. On that line, it's a regular 5V; when looking at the
> total current draw from the PSU, it appears as a "trickle" there.

But (even though someone else who doesn't seem to get the point called me
"pedantic") the current /capacity/ is not the factor that controls the
current /draw/ for standby power that works as designed. The actual current
drawn is determined by the connected load, not by the current capacity of
the standby supply. The moment the current gets actually limited by the
power supply, you are in trouble.

That's exactly the reverse for what's commonly called "trickle power": here
the current drawn is limited by the trickle supply. It's the power supply
that determines the current, not the load -- by design. That's the thing
about "trickle" vs. "standby".

Of course I realize that this has little to do with the core question of
whether or not it is safe to (un)plug harddisks while on standby power. I
just thought I'd contribute to the general level of education ...


> Well, it could be some sort of "ghost power" arrangement I suppose,
> much as some USBs which have external power connections "don't need
> external power" and can run without it.

The term "ghost power" is usually used when the I/O lines of a device have
a signal while the power is down, and internally to the device there's a
current path that now tries to power the device from the I/O line -- which
generally hasn't enough current capacity to fully power the device, and the
internal current path often only powers parts of the device. That's usually
a design flaw (if the situation is a normal operating condition) or a
misuse (if the specs say you shouldn't power the I/O without powering the
device).

(This also applies to your suspicion that IDE connectors may carry signals
even though the harddisk power connectors don't carry power. I'm pretty
sure that harddisk manufacturers would call this a "misuse", because they
don't want to carry the burden of designing their devices to always
withstand this situation. Ask one, if you don't believe me...

In the case of USB, a power line is part of the bus. Devices are allowed to
power themselves through the bus if they don't draw more current than
specified in the USB standard and can be provided by upstream devices.
(That's important, because e.g. an external hub with its own power supply
will be able to provide the full spec current to its downstream devices,
but an external hub that works on USB supply will only be able to provide a
fraction of the full spec current to its downstream devices -- depending on
the current capacity of the upstream device it is connected to.)


> I notice some mobos support wake-up from various IRQs, including the
> IDE controllers

I've never seen a mobo that supports wake-up on IDE controller activity.
Care to share a make/model?

I've also never seen an ATX power supply that would provide the harddisk
power connectors with power in standby mode (that would have to be both 5 V
and 12 V). That would be necessary for wake-up on IDE activity making any
sense.

And, as said above, I'm pretty sure harddisk manufacturers don't like
signal activity on the IDE connector while the disk is not supplied with
power. So any mobo that does this is probably in violation of (most)
harddisks' specs.

Gerhard

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Ge wrote:

> On 8/15/05 12:37:26, cquirke (MVP Windows shell/user) wrote:
>
>> I was referring to the standby power line that you mention a bit
>> further on. On that line, it's a regular 5V; when looking at the
>> total current draw from the PSU, it appears as a "trickle" there.
>
> But (even though someone else who doesn't seem to get the point called me
> "pedantic") the current /capacity/ is not the factor that controls the
> current /draw/ for standby power that works as designed. The actual
> current drawn is determined by the connected load, not by the current
> capacity of the standby supply. The moment the current gets actually
> limited by the power supply, you are in trouble.
>
> That's exactly the reverse for what's commonly called "trickle power":
> here the current drawn is limited by the trickle supply. It's the power
> supply that determines the current, not the load -- by design. That's the
> thing about "trickle" vs. "standby".

Nobody was talking about "trickle power". He was talking about "a trickle
of power". You're being pedantic because you're trying to turn a standard
usage of the word "trickle", to refer to a small flow of something, into a
persnickety technical point about the nomenclature of power supplies.

> Of course I realize that this has little to do with the core question of
> whether or not it is safe to (un)plug harddisks while on standby power. I
> just thought I'd contribute to the general level of education ...
>
>
>> Well, it could be some sort of "ghost power" arrangement I suppose,
>> much as some USBs which have external power connections "don't need
>> external power" and can run without it.
>
> The term "ghost power" is usually used when the I/O lines of a device have
> a signal while the power is down, and internally to the device there's a
> current path that now tries to power the device from the I/O line -- which
> generally hasn't enough current capacity to fully power the device, and
> the internal current path often only powers parts of the device. That's
> usually a design flaw (if the situation is a normal operating condition)
> or a misuse (if the specs say you shouldn't power the I/O without powering
> the device).
>
> (This also applies to your suspicion that IDE connectors may carry signals
> even though the harddisk power connectors don't carry power. I'm pretty
> sure that harddisk manufacturers would call this a "misuse", because they
> don't want to carry the burden of designing their devices to always
> withstand this situation. Ask one, if you don't believe me...

They do carry signal--power down one drive on a cable and the other still
works. Sometimes, however, the drive that is powered down will cause
signal corruption on the line.

> In the case of USB, a power line is part of the bus. Devices are allowed
> to power themselves through the bus if they don't draw more current than
> specified in the USB standard and can be provided by upstream devices.
> (That's important, because e.g. an external hub with its own power supply
> will be able to provide the full spec current to its downstream devices,
> but an external hub that works on USB supply will only be able to provide
> a fraction of the full spec current to its downstream devices -- depending
> on the current capacity of the upstream device it is connected to.)
>
>
>> I notice some mobos support wake-up from various IRQs, including the
>> IDE controllers
>
> I've never seen a mobo that supports wake-up on IDE controller activity.
> Care to share a make/model?

Wake on IRQ. Just tell it to wake on IRQ15 or whatever turns out to be
assigned to the IDE host adapter (interesting that you're so persnickety
about "trickle" but call a host adapter a "controller").

> I've also never seen an ATX power supply that would provide the harddisk
> power connectors with power in standby mode (that would have to be both 5
> V and 12 V). That would be necessary for wake-up on IDE activity making
> any sense.
>
> And, as said above, I'm pretty sure harddisk manufacturers don't like
> signal activity on the IDE connector while the disk is not supplied with
> power. So any mobo that does this is probably in violation of (most)
> harddisks' specs.

How does the motherboard know if there is power being supplied to the disk?

> Gerhard

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/15/05 10:40:57, J. Clarke wrote:

> You're being pedantic here IMO. +5VSB is a "trickle" compared to the normal
> operating power. It seems a pointless argument that you are raising.

I'm not raising an argument about "trickle" vs. "standby". I'm just trying
to explain to people willing to learn what the better (because more
universal, at least among the people who understand about power supplies)
terminology is -- and why. See my other post here for more details (if
you're interested, of course).


> The point is that there is power in the case and on the motherboard with the
> ATX power in the "off" state.

Correct, in that there is power in the case. Wrong, in that this exactly
was the point.

> And depending on what you're doing that standby power can become full
> power very easily and very quickly

Exactly -- depending on what you are doing.

> I've inserted boards into or removed boards from a machine and had it
> power up while I was doing it

See, that's something I wouldn't do, or advise doing -- and I'm not
surprised that it did create problems. Sometimes, understanding the
workings of power supplies /does/ help

> (and don't tell me it can't happen based on some fancy-Dan analytical
> model--in the real world it can and does)

See, what you call my "fancy-Dan analytical model" is actually the
understanding of the inner workings of power supplies and the like. This
tells me that you should /not/ (un)plug PCI boards under standby power
unless you know the mobo and the PCI board very intimately and know what
you're doing. OTOH, it also tells me that it is safe to (un)plug an IDE
harddrive.

> When adding or removing hardware, the best policy is a cold chassis,
> that means either unplugged or hard-off.

That's why I wrote the below, and here I seem to be in complete agreement
with you (even though you didn't seem to see it that way):

"As long as you're not knowing what you're doing, it's a good idea to
always disconnect the power cord of /anything/ you open."

Gerhard

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Ge,

Are you a native speaker of English? The reason I ask is that I find a
certain amount to object to in this post but most of it could be explained
by a slightly imperfect command of the English language. I note that
you're posting from globo, whose home page seems to be in Portuguese, hence
the question. Instead of going on with my comments I wanted to make sure I
was addressing the right issue.


Ge wrote:

> On 8/15/05 10:40:57, J. Clarke wrote:
>
>> You're being pedantic here IMO. +5VSB is a "trickle" compared to the
>> normal
>> operating power. It seems a pointless argument that you are raising.
>
> I'm not raising an argument about "trickle" vs. "standby". I'm just trying
> to explain to people willing to learn what the better (because more
> universal, at least among the people who understand about power supplies)
> terminology is -- and why. See my other post here for more details (if
> you're interested, of course).
>
>
>> The point is that there is power in the case and on the motherboard with
>> the ATX power in the "off" state.
>
> Correct, in that there is power in the case. Wrong, in that this exactly
> was the point.
>
>> And depending on what you're doing that standby power can become full
>> power very easily and very quickly
>
> Exactly -- depending on what you are doing.
>
>> I've inserted boards into or removed boards from a machine and had it
>> power up while I was doing it
>
> See, that's something I wouldn't do, or advise doing -- and I'm not
> surprised that it did create problems. Sometimes, understanding the
> workings of power supplies /does/ help
>
>> (and don't tell me it can't happen based on some fancy-Dan analytical
>> model--in the real world it can and does)
>
> See, what you call my "fancy-Dan analytical model" is actually the
> understanding of the inner workings of power supplies and the like. This
> tells me that you should /not/ (un)plug PCI boards under standby power
> unless you know the mobo and the PCI board very intimately and know what
> you're doing. OTOH, it also tells me that it is safe to (un)plug an IDE
> harddrive.
>
>> When adding or removing hardware, the best policy is a cold chassis,
>> that means either unplugged or hard-off.
>
> That's why I wrote the below, and here I seem to be in complete agreement
> with you (even though you didn't seem to see it that way):
>
> "As long as you're not knowing what you're doing, it's a good idea to
> always disconnect the power cord of /anything/ you open."
>
> Gerhard

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Previously Ge <gefiedler@globo.com> wrote:
> On 8/15/05 13:11:23, Arno Wagner wrote:

>>> While it is theoretically thinkable that a ill-designed mobo supplies its
>>> IDE controlles from ATX standby power, it is still not clear whether this
>>> does any harm to the harddisk. If it does, it probably does so whether or
>>> not you disconnect the harddisk while power is supplied to its IDE
>>> interface -- the damage being done by it being connected, not by the act of
>>> connecting or disconnecting it.

>> To sum up: Connecting or disconnectin HDD power when voltages are
>> present is extremely risky ...

> No contest here. But the question was whether there are any voltages
> present at the harddisk with the ATX power supply in standby mode -- which
> you confirm that there aren't any.

True. I should haveread the posting more carefully.

>> Since this would be complete nonsense, I doubt there is any link.
>> Why spend the extra money to give the controller a power-switch
>> that switches the controller over between +5VSB and +5V, when the
>> controller is perfectly happy to work on +V5?

> Exactly...

>> Actually it is good advice because +5VSB does go to some devices like
>> the PCI cards.

> I wouldn't advise exchanging cards while on standby power. But the question
> was about exchanging drives while on standby.

As you said, no problem. Even unlikely to be a problem if there
was a stupidly designed mainboard with signals on the IDE
bus while in standby.

Arno

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/16/05 10:25:05, J. Clarke wrote:

> Are you a native speaker of English?

No. My native language is German.

> The reason I ask is that I find a certain amount to object to in this
> post but most of it could be explained by a slightly imperfect command
> of the English language.

I would appreciate if you found the time to point out what you think is
expressed (or understood) not quite right.

OTOH, I'm pretty sure that my /technical/ English is pretty good. I've been
writing technical papers for US companies for some time -- and I've been
reviewing technical papers written by native speakers. While it seems that
I couldn't manage to completely get rid of creating some kind of "odd
feeling" on occasion, the terminology and the grammatical constructs I'm
using seem to be correct.

Gerhard

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/16/05 10:05:48, J. Clarke wrote:

> Nobody was talking about "trickle power". He was talking about "a trickle
> of power". You're being pedantic because you're trying to turn a standard
> usage of the word "trickle", to refer to a small flow of something, into a
> persnickety technical point about the nomenclature of power supplies.
>
>> Of course I realize that this has little to do with the core question of
>> whether or not it is safe to (un)plug harddisks while on standby power. I
>> just thought I'd contribute to the general level of education ...

I find your opinion that I'm "trying to turn a standard usage of the word
'trickle' [...] into a persnickety technical point about the nomenclature
of power supplies" not quite compatible with the paragraph of mine that was
right following your opinion. I wouldn't assert that "this has little to do
with the core question of whether or not it is safe to (un)plug harddisks
while on standby power" if I really wanted to turn this into a "persnickety
technical point".

The reason I was trying to point out the difference is that from a
technical (electronic) point of view, there seems to be quite a confusion
in this thread about ATX standby power and its "powers", so to speak. So I
tried to bring in some foundation knowledge. It's yours to take or leave.

I don't quite understand why you object, or to what. It seems that you
don't object to the technical content; at least you haven't brought forth
any technical objections to my explanations of the differences between
trickle and standby power. It may not help you, but it may help others --
if it is correct. If it is not correct, then please start saying what's
wrong. If it is correct, maybe stop objecting and focus on what you want to
object to.


>> The term "ghost power" is usually used when the I/O lines of a device have
>> a signal while the power is down, and internally to the device there's a
>> current path that now tries to power the device from the I/O line -- which
>> generally hasn't enough current capacity to fully power the device, and
>> the internal current path often only powers parts of the device. That's
>> usually a design flaw (if the situation is a normal operating condition)
>> or a misuse (if the specs say you shouldn't power the I/O without powering
>> the device).
>>
>> (This also applies to your suspicion that IDE connectors may carry signals
>> even though the harddisk power connectors don't carry power. I'm pretty
>> sure that harddisk manufacturers would call this a "misuse", because they
>> don't want to carry the burden of designing their devices to always
>> withstand this situation. Ask one, if you don't believe me...
>
> They do carry signal--power down one drive on a cable and the other still
> works. Sometimes, however, the drive that is powered down will cause
> signal corruption on the line.

I'm not sure what you mean. The situation where the harddisk power
connectors of an ATX power supply don't carry power is in standby mode and
when off. In neither of these situations, the IDE connectors of the mobo
carry any signals (unless you can show some evidence that they do) -- and
definitely no other harddisks are working.

When you say that sometimes the powered-down drive will cause signal
corruption on the IDE bus is a confirmation of my point (see below) that a
drive connected to the IDE bus without being connected to power is in an
operation mode not supported or guaranteed to work by the drive
manufacturer.


>> I've never seen a mobo that supports wake-up on IDE controller activity.
>> Care to share a make/model?
>
> Wake on IRQ. Just tell it to wake on IRQ15 or whatever turns out to be
> assigned to the IDE host adapter (interesting that you're so persnickety
> about "trickle" but call a host adapter a "controller").

Just because you can tell your mobo to wake up on the IDE controller's
interrupt (more to the use of the term "IDE controller" below) doesn't mean
it actually will wake up. In standby, there's no power to the disks,
therefore the disks won't initiate any activity on the IDE bus, therefore
the IDE controller won't create any interrupt -- if the IDE controller is
powered up at all in standby, which is doubtful.

So, to summarize, for a "wake-up on IDE" feature to work, these are the
necessary conditions:
- There must be the possibility of IDE activity in standby mode.
- This requires that there is a device on the IDE bus that is powered in
standby mode.
- It also requires that the IDE controller is powered in standby mode.
- The mobo/BIOS must support wake up on activity from the IDE controller.

I don't know an ATX mobo/power supply combo that would satisfy these
conditions. I doubt you know one, either. If you do, it should be easy to
post a link or two to the manufacturer's site where these outstanding and
quite rare features are described.


Now to your question about "host adapter" vs. "controller". They are not
the same, and I did use the term "IDE controller" quite on purpose. I was
not talking about all of the IDE host adapter, I was talking specifically
about the IDE controller. Every IDE host adapter contains an IDE
controller. Google for "IDE controller" (use the quotes to limit the
results) and you'll see that there is in fact something like that out there
-- and that's what I was referring to.

To make a somewhat longer story short, the "IDE controller" of a mobo is
usually an IC (or part of an IC) that performs the functions of the IDE
interface controller -- in an IDE host adapter. Maybe something like this
http://www.smsc.com/main/catalog/slc90e66.html (note the term "IDE
Controller" right in the title of the page).

(Who's trying to be "persnickety" about the use of the term "controller"?



>> And, as said above, I'm pretty sure harddisk manufacturers don't like
>> signal activity on the IDE connector while the disk is not supplied with
>> power. So any mobo that does this is probably in violation of (most)
>> harddisks' specs.
>
> How does the motherboard know if there is power being supplied to the disk?

This is all a discussion about ATX standby power, remember? So of course
the mobo knows when the power supply is in standby mode, and it knows that
in standby mode the disks are not supplied with power from the ATX power
supply. It also knows when the power supply is in normal mode, and it
infers that any harddisk connected to its IDE interfaces is supplied with
proper power.

Of course you can connect a harddisk to the IDE interface and /not/ connect
it to the power supply. In this case, there is indeed signal activity on
the harddisk's IDE interface while the disk is not supplied with power. But
as I said, I think that you'll find that most disk manufacturers will
consider this an out-of-spec operation mode and won't guarantee proper
function of the drive or its IDE interface. I'll be happy to read up on
harddisk manufacturer links stating the contrary.

Gerhard

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Ge wrote:

> On 8/16/05 10:05:48, J. Clarke wrote:
>
>> Nobody was talking about "trickle power". He was talking about "a
>> trickle
>> of power". You're being pedantic because you're trying to turn a
>> standard usage of the word "trickle", to refer to a small flow of
>> something, into a persnickety technical point about the nomenclature of
>> power supplies.
>>
>>> Of course I realize that this has little to do with the core question of
>>> whether or not it is safe to (un)plug harddisks while on standby power.
>>> I just thought I'd contribute to the general level of education ...
>
> I find your opinion that I'm "trying to turn a standard usage of the word
> 'trickle' [...] into a persnickety technical point about the nomenclature
> of power supplies" not quite compatible with the paragraph of mine that
> was right following your opinion. I wouldn't assert that "this has little
> to do with the core question of whether or not it is safe to (un)plug
> harddisks while on standby power" if I really wanted to turn this into a
> "persnickety technical point".
>
> The reason I was trying to point out the difference is that from a
> technical (electronic) point of view, there seems to be quite a confusion
> in this thread about ATX standby power and its "powers", so to speak. So I
> tried to bring in some foundation knowledge. It's yours to take or leave.
>
> I don't quite understand why you object, or to what. It seems that you
> don't object to the technical content; at least you haven't brought forth
> any technical objections to my explanations of the differences between
> trickle and standby power. It may not help you, but it may help others --
> if it is correct. If it is not correct, then please start saying what's
> wrong. If it is correct, maybe stop objecting and focus on what you want
> to object to.

I've already addressed this in another post.

>>> The term "ghost power" is usually used when the I/O lines of a device
>>> have a signal while the power is down, and internally to the device
>>> there's a current path that now tries to power the device from the I/O
>>> line -- which generally hasn't enough current capacity to fully power
>>> the device, and the internal current path often only powers parts of the
>>> device. That's usually a design flaw (if the situation is a normal
>>> operating condition) or a misuse (if the specs say you shouldn't power
>>> the I/O without powering the device).
>>>
>>> (This also applies to your suspicion that IDE connectors may carry
>>> signals even though the harddisk power connectors don't carry power. I'm
>>> pretty sure that harddisk manufacturers would call this a "misuse",
>>> because they don't want to carry the burden of designing their devices
>>> to always withstand this situation. Ask one, if you don't believe me...
>>>
>>
>> They do carry signal--power down one drive on a cable and the other still
>> works. Sometimes, however, the drive that is powered down will cause
>> signal corruption on the line.
>
> I'm not sure what you mean. The situation where the harddisk power
> connectors of an ATX power supply don't carry power is in standby mode and
> when off. In neither of these situations, the IDE connectors of the mobo
> carry any signals (unless you can show some evidence that they do) -- and
> definitely no other harddisks are working.

You neglect the possibility that the signal cable is connected but the power
cable is not. There are very few motherboards that can detect this
situation.

> When you say that sometimes the powered-down drive will cause signal
> corruption on the IDE bus is a confirmation of my point (see below) that a
> drive connected to the IDE bus without being connected to power is in an
> operation mode not supported or guaranteed to work by the drive
> manufacturer.

In dealing with practical matters of technology, one is concerned with what
is, not with what manufacturers "support or guarantee".

>>> I've never seen a mobo that supports wake-up on IDE controller activity.
>>> Care to share a make/model?
>>
>> Wake on IRQ. Just tell it to wake on IRQ15 or whatever turns out to be
>> assigned to the IDE host adapter (interesting that you're so persnickety
>> about "trickle" but call a host adapter a "controller").
>
> Just because you can tell your mobo to wake up on the IDE controller's
> interrupt (more to the use of the term "IDE controller" below) doesn't
> mean it actually will wake up. In standby, there's no power to the disks,
> therefore the disks won't initiate any activity on the IDE bus, therefore
> the IDE controller won't create any interrupt -- if the IDE controller is
> powered up at all in standby, which is doubtful.

The "IDE controller" is to a substantial extent a PCI-to-ISA bridge. Why
would it _not_ be powered to the same extent that the rest of the PCI bus
is powered?

> So, to summarize, for a "wake-up on IDE" feature to work, these are the
> necessary conditions:
> - There must be the possibility of IDE activity in standby mode.

Only to the extent that an interrupt can be generated.

> - This requires that there is a device on the IDE bus that is powered in
> standby mode.

Only to the extent that an interrupt can be generated.

> - It also requires that the IDE controller is powered in standby mode.

Host adapter.

> - The mobo/BIOS must support wake up on activity from the IDE controller.

No. Only on activity on a particular IRQ.

> I don't know an ATX mobo/power supply combo that would satisfy these
> conditions. I doubt you know one, either. If you do, it should be easy to
> post a link or two to the manufacturer's site where these outstanding and
> quite rare features are described.

Only if it was "outstanding or quite rare". Wake on interrupt is a common
feature.

> Now to your question about "host adapter" vs. "controller". They are not
> the same, and I did use the term "IDE controller" quite on purpose. I was
> not talking about all of the IDE host adapter, I was talking specifically
> about the IDE controller. Every IDE host adapter contains an IDE
> controller. Google for "IDE controller" (use the quotes to limit the
> results) and you'll see that there is in fact something like that out
> there -- and that's what I was referring to.

The whole point of IDE was that it could be very cheaply connected to an ISA
bus. You could take a first generation IDE drive and an ISA motherboard
and unsolder a connector from the motherboard, solder in a cable, and plug
the other end of that cable into a drive and it would work fine. IDE host
adapters for the ISA bus were simple boards that carried the ISA card edge
connector into a pin header for a cable.

When PCI came about they changed into ISA-to-PCI bridges. But the
controller remains on the disk.

> To make a somewhat longer story short, the "IDE controller" of a mobo is
> usually an IC (or part of an IC) that performs the functions of the IDE
> interface controller -- in an IDE host adapter. Maybe something like this
> http://www.smsc.com/main/catalog/slc90e66.html (note the term "IDE
> Controller" right in the title of the page).

Sloppy terminology. All it does it pass commands from the PCI bus to the
IDE bus. All the controlling is done on the disk.

> (Who's trying to be "persnickety" about the use of the term "controller"?
>

You're the one who started demanding precise use of language.

>>> And, as said above, I'm pretty sure harddisk manufacturers don't like
>>> signal activity on the IDE connector while the disk is not supplied with
>>> power. So any mobo that does this is probably in violation of (most)
>>> harddisks' specs.
>>
>> How does the motherboard know if there is power being supplied to the
>> disk?
>
> This is all a discussion about ATX standby power, remember? So of course
> the mobo knows when the power supply is in standby mode, and it knows that
> in standby mode the disks are not supplied with power from the ATX power
> supply. It also knows when the power supply is in normal mode, and it
> infers that any harddisk connected to its IDE interfaces is supplied with
> proper power.
>
> Of course you can connect a harddisk to the IDE interface and /not/
> connect it to the power supply. In this case, there is indeed signal
> activity on the harddisk's IDE interface while the disk is not supplied
> with power. But as I said, I think that you'll find that most disk
> manufacturers will consider this an out-of-spec operation mode and won't
> guarantee proper function of the drive or its IDE interface. I'll be happy
> to read up on harddisk manufacturer links stating the contrary.

So when that is done, how does the motherboard know that is has been done so
as to not send signals?

> Gerhard

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

 

[GE]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On 8/16/05 10:05:48, J. Clarke wrote:

Let me just clarify this a bit more...

> Nobody was talking about "trickle power". He was talking about "a trickle
> of power".

You are of course correct here.

> You're being pedantic ...

Maybe... but that's not a crime, is it? And with technical issues, it's
better to be pedantic and correct than to be lax and wrong.

> ... because you're trying to turn a standard usage of the word "trickle", to
> refer to a small flow of something, into a persnickety technical point
> about the nomenclature of power supplies.

Definitely not.

The problem I saw (and tried to get out of the way of this discussion) is
that the term "trickle of power" seems to create in some minds the notion
that while this "trickle of power" is fed into the mobo there is some kind
of a trickle of power everywhere on the mobo.

That's why I tried to explain that there isn't really a "trickle"; there is
a well-defined standby power supply. While it is in fact a trickle compared
to the full power fed into the system when not in standby mode, it doesn't
trickle all over the mobo. It is only present in well-defined locations
(even though they may not always be as well-known as they are
well-defined).

Everything else -- everything that's not connected to the ATX 5 V standby
power line -- is off. No ifs and buts, not trickles, no nothing -- just
off. Specifically, the peripheral power connectors (the ones with the four
wires; usually red, yellow and black) are off, and so are all the harddisks
connected to them. Not even a trickle of power here.

That's why I wanted to get the term "trickle" out of the way. I think it
hinders the factual discussion about the ATX standby mode and its
implications and creates misunderstandings.

Gerhard

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Ge <gefiedler@globo.com> wrote in message
news:118axswn2wm28$.ilbwci5uiyjt$.dlg@40tude.net...
> J. Clarke wrote

>> Are you a native speaker of English?

> No. My native language is German.

>> The reason I ask is that I find a certain amount to object
>> to in this post but most of it could be explained by a
>> slightly imperfect command of the English language.

> I would appreciate if you found the time to point out what
> you think is expressed (or understood) not quite right.

> OTOH, I'm pretty sure that my /technical/ English is pretty good.
> I've been writing technical papers for US companies for some time
> -- and I've been reviewing technical papers written by native speakers.
> While it seems that I couldn't manage to completely get rid of creating
> some kind of "odd feeling" on occasion, the terminology and the
> grammatical constructs I'm using seem to be correct.

Yeah, he is just being nasty, your english is quite a bit better
than many native english speakers can manage, including him.