Help: 40mb Instead of 80mb Data Rate/"Active negation" Pro..

Toggle sidebar Toggle sidebar
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

Someone is testing out some LVD SCSI drives I gave him, and he told me
that the data rate with the cable I gave him is 40mb instead of the
advertised 80mb per second.

He said he thinks that some sort of "Active Negation" terminator is
needed, and I was wondering if someone could elaborate on what these
are and where I may be able to find them.(Or come up with any other
solution to overcome this problem).

The hardware involved is as follows:
1) Four Seagate 18.21 SCSI drives st118273lC.
2) Four SCA Adaptors(Ultra4 320/m SCSI compliant).
3) One Amphenol Spectra Strip.(AWM 80C 1131941 CSA AWM 1 A80C 150V FT
1).
It has a terminator, but apparently it is the incorrect one, and needs
to be changed.

Any help would be greatly appreciated.

Thanks a lot.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

Darren Harris wrote:
> Someone is testing out some LVD SCSI drives I gave him, and he told me
> that the data rate with the cable I gave him is 40mb instead of the
> advertised 80mb per second.
>
> He said he thinks that some sort of "Active Negation" terminator is
> needed, and I was wondering if someone could elaborate on what these
> are and where I may be able to find them.(Or come up with any other
> solution to overcome this problem).
>
> The hardware involved is as follows:
> 1) Four Seagate 18.21 SCSI drives st118273lC.
> 2) Four SCA Adaptors(Ultra4 320/m SCSI compliant).
> 3) One Amphenol Spectra Strip.(AWM 80C 1131941 CSA AWM 1 A80C 150V FT
> 1).
> It has a terminator, but apparently it is the incorrect one, and needs
> to be changed.
>
> Any help would be greatly appreciated.
>
> Thanks a lot.
>
> Darren Harris
> Staten Island, New York.

Any markings on the terminator which might help us identify it's
specifications?
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

> Any markings on the terminator which might help us identify it's
> specifications?

On one side it says "ACTIVE", and on the other side it has the number
"22.30037.011".

Thanks.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408041943.520b46d2@posting.google.com
> Someone is testing out some LVD SCSI drives I gave him, and he told me
> that the data rate with the cable I gave him is 40MB/s instead of the
> advertised 80MB/s.
>
> He said he thinks that some sort of "Active Negation" terminator is
> needed, and I was wondering if someone could elaborate on what these
> are and where I may be able to find them.(Or come up with any other
> solution to overcome this problem).

Although an LVD terminator is of the sort "active negation" you need
a specific LVD or LVD/SE terminator.

Terminators that say "Active" on them are SE.

>
> The hardware involved is as follows:
> 1) Four Seagate 18.21 SCSI drives st118273lC.
> 2) Four SCA Adaptors(Ultra4 320/m SCSI compliant).
> 3) One Amphenol Spectra Strip.(AWM 80C 1131941 CSA AWM 1 A80C 150V FT
> 1).
> It has a terminator, but apparently it is the incorrect one, and needs
> to be changed.
>
> Any help would be greatly appreciated.
>
> Thanks a lot.
>
> Darren Harris
> Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408050239.7c19456a@posting.google.com
> > Any markings on the terminator which might help us identify it's
> > specifications?
>
> On one side it says "ACTIVE",

Then it is SE.
Get a LVD cable with LVD or LVD/SE terminator attached to it.
These are usually available cheap when coming from surplus.

> and on the other side it has the number "22.30037.011".
>
> Thanks.
>
> Darren Harris
> Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

> Someone is testing out some LVD SCSI drives I gave him, and he told me
> that the data rate with the cable I gave him is 40mb instead of the
> advertised 80mb per second.

Are you using LVD cables? Some LVD drives will work at 80MB/sec with
non-LVD cables (I have a Compaq 4GB that does) but most drives will fall
back to the fastest non-LVD speed, i.e. 40MB/sec. If the cable is LVD
compatible, it should have the correct terminator. If it's wrong, you
usually just get data errors rather than a fallback to 40MB/sec.

Also make sure the controller and/or the drive isn't set to Ultra Wide,
as you can disable LVD mode on most controllers and drives via jumpers
or BIOS settings.

Cheers,
Adam.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Adam Nielsen" <a.nielsen@optushome.com.rem.ove.au> wrote in message news:20040805213311.2c1ee410.a.nielsen@optushome.com.rem.ove.au
> > Someone is testing out some LVD SCSI drives I gave him, and he told me
> > that the data rate with the cable I gave him is 40mb instead of the
> > advertised 80mb per second.
>

> Are you using LVD cables? Some LVD drives will work at 80MB/sec with
> non-LVD cables (I have a Compaq 4GB that does) but most drives will fall
> back to the fastest non-LVD speed, i.e. 40MB/sec.

Pure nonsense. Fallback (Domain validation) only occurs with Ultra160.

> If the cable is LVD compatible, it should have the correct terminator.

Or not. Not all cables come with terminators.

> If it's wrong, you usually just get data errors rather than a fallback
> to 40MB/sec.

Nonsense. Just a moment ago you said the complete opposite.
You make things up where you stand, don't you.

>
> Also make sure the controller and/or the drive isn't set to Ultra Wide,
> as you can disable LVD mode on most controllers and drives via jumpers

> or BIOS settings.

No you can't. But you can disable higher than 40MB/s bus transfer rates.

>
> Cheers,
> Adam.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message news:<2net7nF4d3mU4@uni-berlin.de>...
> "Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408050239.7c19456a@posting.google.com
> > > Any markings on the terminator which might help us identify it's
> > > specifications?
> >
> > On one side it says "ACTIVE",
>
> Then it is SE.
> Get a LVD cable with LVD or LVD/SE terminator attached to it.
> These are usually available cheap when coming from surplus.

The ones I've found on the internet so far are expensive. Can you
recommend any sources?

And I assume that just getting a termiinator and replacing the one
already on the cable is not a good option, correct?

Thanks a lot.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message
news:9437a27c.0408060258.65798c87@posting.google.com...

> > Then it is SE.
> > Get a LVD cable with LVD or LVD/SE terminator attached to it.
> > These are usually available cheap when coming from surplus.
>
> The ones I've found on the internet so far are expensive. Can you
> recommend any sources?
>
There is nothing wrong with the "new" surplus U2W cables. The ones I got were
made for HP.

> And I assume that just getting a termiinator and replacing the one
> already on the cable is not a good option, correct?
>
The cable+term is probably cheaper.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Eric Gisin" <ericgisin@graffiti.net> wrote in message news:<cf09fe02nld@enews2.newsguy.com>...
> "Darren Harris" <Searcher7@mail.con2.com> wrote in message
> news:9437a27c.0408060258.65798c87@posting.google.com...
>
> > > Then it is SE.
> > > Get a LVD cable with LVD or LVD/SE terminator attached to it.
> > > These are usually available cheap when coming from surplus.
> >
> > The ones I've found on the internet so far are expensive. Can you
> > recommend any sources?
> >
> There is nothing wrong with the "new" surplus U2W cables. The ones I got were
> made for HP.
>
> > And I assume that just getting a termiinator and replacing the one
> > already on the cable is not a good option, correct?
> >
> The cable+term is probably cheaper.

Any idea on the best place to get it?

Thanks.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message
news:9437a27c.0408061654.5e7898db@posting.google.com...
> "Eric Gisin" <ericgisin@graffiti.net> wrote in message
news:<cf09fe02nld@enews2.newsguy.com>...

> > There is nothing wrong with the "new" surplus U2W cables. The ones I got
were
> > made for HP.
> >
> > > And I assume that just getting a termiinator and replacing the one
> > > already on the cable is not a good option, correct?
> > >
> > The cable+term is probably cheaper.
>
> Any idea on the best place to get it?
>
Whenever you are buying technology over 5 years old the place is ebay. I'm
sure there are alternatives on the web, but it takes hours to find what you
want.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408060258.65798c87@posting.google.com...
> "Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message news:<2net7nF4d3mU4@uni-berlin.de>...
> > "Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408050239.7c19456a@posting.google.com
> > > > Any markings on the terminator which might help us identify it's
> > > > specifications?
> > >
> > > On one side it says "ACTIVE",
> >
> > Then it is SE.
> > Get a LVD cable with LVD or LVD/SE terminator attached to it.
> > These are usually available cheap when coming from surplus.
>
> The ones I've found on the internet so far are expensive. Can you
> recommend any sources?

Punch in E124936 in Google.
Or use Compaq or HP or surplus in combination with your LVD cable search.

>
> And I assume that just getting a termiinator and replacing the one
> already on the cable is not a good option, correct?

That's fine too. But you'll probably pay full price for it.
You should be able to get a terminated cable for 5-10 dollars.
I bought mine for 5 Euro at a computer fair.

>
> Thanks a lot.
>
> Darren Harris
> Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

> > Are you using LVD cables? Some LVD drives will work at 80MB/sec
> > with non-LVD cables (I have a Compaq 4GB that does) but most drives
> > will fall back to the fastest non-LVD speed, i.e. 40MB/sec.

> Pure nonsense. Fallback (Domain validation) only occurs with Ultra160.

Sorry yes, you're right. I was thinking of the fallback to non-LVD
speeds that occur when there's a SE drive in the chain, which is
(probably) not the case here (unless one of the drives is set forced to
SE, see my last point.)

> > If the cable is LVD compatible, it should have the correct
> > terminator.
> Or not. Not all cables come with terminators.

Well, obviously if it doesn't have a terminator then it doesn't have a
terminator, but if it does come with a terminator it should be the right
one.

> > If it's wrong, you usually just get data errors rather than a
> > fallback to 40MB/sec.
> Nonsense. Just a moment ago you said the complete opposite.
> You make things up where you stand, don't you.

My my, we are on the offensive today aren't we??? There's no need to
attack me just because you disagree with something I said.

A moment ago I said that most drives will fall back if using the wrong
cable, and now I said that if you're using the right cable but a dodgy
terminator you get data errors - that's not the opposite...

> > Also make sure the controller and/or the drive isn't set to Ultra
> > Wide, as you can disable LVD mode on most controllers and drives via
> > jumpers or BIOS settings.

> No you can't. But you can disable higher than 40MB/s bus transfer
> rates.

Well obviously LVD == higher than 40MB/s transfer rates, so whatever the
option is called it has the same effect. Likewise the jumper on the
drive is labelled "Force single ended" but it'll still effectively
disable LVD modes.

Cheers,
Adam.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

"Adam Nielsen" <a.nielsen@optushome.com.rem.ove.au> wrote in message
news:20040807122716.54d2bf7a.a.nielsen@optushome.com.rem.ove.au...
> > > Are you using LVD cables? Some LVD drives will work at 80MB/sec
> > > with non-LVD cables (I have a Compaq 4GB that does) but most drives
> > > will fall back to the fastest non-LVD speed, i.e. 40MB/sec.
>
> > Pure nonsense. Fallback (Domain validation) only occurs with Ultra160.
>
> Sorry yes, you're right. I was thinking of the fallback to non-LVD
> speeds that occur when there's a SE drive in the chain, which is
> (probably) not the case here (unless one of the drives is set forced to
> SE, see my last point.)

Yes, but then NO drive will work at 80MB/sec bus transfer
as all are forced to SE mode. Same with a SE mode terminator.

If you have a substandard cable and all drives are LVD then you may get
data transfer problems with U2W. You get a lower than optimal bus trans-
fer speed -but still in LVD mode- with Ultra160 due to Domain Validation.

>
> > > If the cable is LVD compatible, it should have the correct terminator.
> >
> > Or not. Not all cables come with terminators.
>
> Well, obviously if it doesn't have a terminator then it doesn't have a
> terminator,

But a terminator is then added to it. This is where confusion may take place.

> but if it does come with a terminator it should be the right one.

If it comes with it then usually it is the right one.

>
> > > If it's wrong, you usually just get data errors rather than a
> > > fallback to 40MB/sec.
> >
> > Nonsense. Just a moment ago you said the complete opposite.
> > You make things up where you stand, don't you.
>
> My my, we are on the offensive today aren't we??? There's no need to
> attack me just because you disagree with something I said.

I don't disagree, you are flat false. To be so wrong on al-
most everything it is obvious that you are making it all up.

>
> A moment ago I said that most drives will fall back if using the wrong
> cable,

Which was wrong.

> and now I said that if you're using the right cable but a

> dodgy terminator

You said "correct terminator".

> you get data errors -

Which is also wrong. A SE terminator forces fallback to SE mode.

> that's not the opposite...

Actually it is as you have that completely mixed up:
Wrong (substandard) cable: errors.
Wrong terminator: fallback to SE mode.

>
> > > Also make sure the controller and/or the drive isn't set to Ultra
> > > Wide, as you can disable LVD mode on most controllers and drives
> > > via jumpers

Jumpers yes, bios no.

> > > or BIOS settings.
>
> > No you can't. But you can disable higher than 40MB/s bus transfer
> > rates.
>
> Well obviously LVD == higher than 40MB/s transfer rates,

Yes, but lower or equal than 40MB/s isn't automatically Single Ended.

> so whatever the option is called it has the same effect.

Nope.
LVD 40MB/s and SE 40MB/s may be the same speed but not the same mode.

> Likewise the jumper on the drive is labelled "Force single ended" but it'll
> still effectively disable LVD modes.

Gee, maybe that is why they called it Force SE and not force 40MB/s, don't
you think?

>
> Cheers,
> Adam.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt,comp.hardware (More info?)

Someone should come up with a chart to keep track of all this.

Nevertheless, from what you said, it comes down to getting a cable
with a terminator that says "Active Termination". Any others probably
will not give me the 80mb per sec. data transfer rates, correct?

The part number you gave me(E124936) didn't bring up much. I need a
cable that allows for at least 4 devices. If I could get the correct
terminators for the 6 device cables I already have, I'd be set.

I'd also like to point out that a couple of previous posts in the
Google newsgroups state that the cable you mentioned(E124936) is not
LVD compatible.

I want to get a couple from Ebay, but I doubt many sellers put all of
the cable info in their ads, and knowing what I'm looking at is
difficult.(I just don't want to be stuck with more cables that are the
wrong type).

Thanks a lot.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

A search of "LVD SCSI cable" came up with perfect match:
cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=3496922835

"Darren Harris" <Searcher7@mail.con2.com> wrote in message
news:9437a27c.0408071402.7c4bf7a5@posting.google.com...
>
> I want to get a couple from Ebay, but I doubt many sellers put all of
> the cable info in their ads, and knowing what I'm looking at is
> difficult.(I just don't want to be stuck with more cables that are the
> wrong type).
>
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

?!?

But "Active Negation" is nowhere in that ad.

What terms would I have to see in an ad in order to be sure thble has
"Active Negation terminators?

Thanks a lot.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

Perhaps you should re-read the thread then. Nobody else confirmed this guys
statement about "active negation". In fact, I have never seen this label on a
LVD cable+terminator.

If someone sells you an LVD cable without the correct terminator, you return
it.

"Darren Harris" <Searcher7@mail.con2.com> wrote in message
news:9437a27c.0408111448.18d4619b@posting.google.com...
>
> The guy who tested the drives is the one who told me that the
> terminator must say "Active Negation" on it in order to be sure that
> it is an "Active Negation" terminator, so that is the term I was
> putting in my Ebay search.
>
> Now since all LVD cables don't necessarily have the correct (LVD)
> termintor attached(as per your words), I didn't want to take a chance
> on getting the wrong cables again.
>
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

> The words "active termination"
> don't necessarily have to
> appear on the terminator or in
> an eBay auction description --
> terms like "LVD" or "LVD/SE"
> imply the proper kind of
> termination for LVD operation,
> so unless the seller is
> tampering (e.g. plugging an SE
> terminator into the far end
> of what started life as an LVD
> cable), then the cable will
> allow LVD operation assuming
> it's in working condition.

Actually the phrase in question is "Active Negation", not "Active Termination".

> In my experience (which is a
> tiny fraction of Folkert's,
> Eric's, or Ron's), the most
> common type of LVD cable is
> pretty delicate and easily
> damaged, much less durable
> than the plain ribbon cables
> used for SE drives. They
> usually comprise multiple
> twisted pairs held in place by
> a transparent jacket that
> tends dry out, become brittle,
> and start to let go with age
> and exposure to heat -- that's
> why imo you're much better off
> buying a new or NOS (new, old
> stock) surplus item than
> something that's already been
> cooking in somebody's server
> for a few years.

The cables I bid on are new.

Thanks.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Eric Gisin" <ericgisin@graffiti.net> wrote in message news:<cfea0e0230q@enews4.newsguy.com>...
> Perhaps you should re-read the thread then. Nobody else confirmed this guys
> statement about "active negation".

No need to re-read. That's right. No one addressed it at all, so I
assumed that he was correct.

> In fact, I have never seen this label on a LVD cable+terminator.

http://www.sidewindercomputers.com/ul160seacneg.html

> If someone sells you an LVD cable without the correct terminator, you return
> it.

I'd rather get it right the first time. Hence this thread.

Darren Harris
Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message news:9437a27c.0408120036.3ffb2f99@posting.google.com
> "Eric Gisin" <ericgisin@graffiti.net> wrote in message news:<cfea0e0230q@enews4.newsguy.com>...
>> Perhaps you should re-read the thread then. Nobody else confirmed this guys
>> statement about "active negation".
>
> No need to re-read.

Good choice. One might embarrass oneself if one did and anyone knows
that when one closes ones eyes it just goes away conveniently, eh Darren?

> That's right.

Clueless.

> No one addressed it at all, so I assumed that he was correct.

*I* addressed it, you arrogant prick: news:2net7mF4d3mU2@uni-berlin.de

"
Although an LVD terminator is of the sort "active negation" you need
a specific LVD or LVD/SE terminator.
Terminators that say "Active" on them are SE.
"

>
>> In fact, I have never seen this label on a LVD cable+terminator.
>
> http://www.sidewindercomputers.com/ul160seacneg.html

Uhuh, and where is the cable in that, evidently better reader?

This is just a trading company that sells an OEM LVD/SE terminator under
its own label, adding print-on specifications that should be selfevident just
to make it appear more appealing than any other LVD/SE terminator that
is the same to theirs. They all use the same or similar LVD/SE terminator
chips that are active negation and switch automatically for SE, LVD and HVD.

>
>> If someone sells you an LVD cable without the correct terminator, you return
>> it.
>
> I'd rather get it right the first time. Hence this thread.
>
> Darren Harris
> Staten Island, New York.
 
G

Guest

Guest
Archived from groups: comp.periphs.scsi,alt.comp.hardware.pc-homebuilt (More info?)

"Darren Harris" <Searcher7@mail.con2.com> wrote in message
news:9437a27c.0408130235.36a4fecc@posting.google.com...
> "Folkert Rienstra" <see_reply-to@myweb.nl> wrote in message
news:<2o2dlaF61ksjU2@uni-berlin.de>...

> > *I* addressed it, you arrogant prick: news:2net7mF4d3mU2@uni-berlin.de
>
> It's so easy for any little punk to exhibit balls by resorting to name
> calling from thousands of miles away and behind a keyboard. You're
> still wrong.
>
> > "
> > Although an LVD terminator is of the sort "active negation" you need
> > a specific LVD or LVD/SE terminator.
> > Terminators that say "Active" on them are SE.
> > "
This is pretty clear. You need a terminator that says LVD, like many of us
have said. "active negation" is insufficient.
>
> Now how does that quote address the notion that the "terminator must
> say "Active Negation" on it in order to be sure that it is an "Active
> Negation" terminator?
>
> These posts are archived, so your stupidity will be available for
> everyone to see for a long, long time.
>
Rather, your moronic trolling will be recorded forever.
 
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom