PSU tolerance - 10%?

[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

I always thought over 10% out on a voltage was a problem. MY PSU (300 watt) is just over 10% on occasion (the -5V line). Will this break anything?

As per signature, no fans please!!!!

--
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[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

Peter Hucker wrote:
> I always thought over 10% out on a voltage was a problem. MY PSU
> (300 watt) is just over 10% on occasion (the -5V line). Will this
> break anything?
>
> As per signature, no fans please!!!!

The negative voltages are not used on nearly all current systems
(holdover from the ISA days), so it's not important what they are
(unless it's a really old system).
The +3.3V and +5V rails should be within 5% of nominal, while +12V can
vary by as much as 10%.
Your +3.3V and +5V are really close to the low edge. A larger PSU would
probably bring those voltages closer to where they should be.

 

[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

On Fri, 02 Jul 2004 16:46:26 +0100, Peter Hucker <hucker@clara.co.uk> wrote:

> I always thought over 10% out on a voltage was a problem. MY PSU (300 watt) is just over 10% on occasion (the -5V line). Will this break anything?
>
> As per signature, no fans please!!!!

Forgot jpg.

http://www.hucker.plus.com/temp/dials.jpg

--
13 parrots and rising http://www.petersparrots.com
93 silly video clips http://www.insanevideoclips.com
1259 digital photos http://www.petersphotos.com
Served from a quad watercooled dual 2.8GHz silent Athlon with a half terrabyte Raid.

When you own Llamas... spit happens

 

[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

Voltage Rail Tolerance.
+5VDC ± 5 %

-5VDC (if used) ± 10 %

+12VDC ± 5 %

-12VDC ± 10 %

+3.3VDC ± 4 %

+5VSB ± 5 %





>> I always thought over 10% out on a voltage was a problem. MY PSU (300
>> watt) is just over 10% on occasion (the -5V line). Will this break
>> anything?
>>

 

[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

On Fri, 2 Jul 2004 12:21:30 -0400, ICee <icee@thelight.invalid> wrote:

> Peter Hucker wrote:
>> I always thought over 10% out on a voltage was a problem. MY PSU
>> (300 watt) is just over 10% on occasion (the -5V line). Will this
>> break anything?
>>
>> As per signature, no fans please!!!!
>
> The negative voltages are not used on nearly all current systems
> (holdover from the ISA days), so it's not important what they are
> (unless it's a really old system).

I found a pdf that said that about the -5V, but not the -12. I'll assume you are correct and the no load is screwing up the PSU's regulation.

> The +3.3V and +5V rails should be within 5% of nominal,

They are 99% of the time. In the last 12 hours, the 5V dipped below 5% once (for 2 seconds).

> while +12V can
> vary by as much as 10%.

12 is the most accurate one!

> Your +3.3V and +5V are really close to the low edge. A larger PSU

I blew it up!

> would probably bring those voltages closer to where they should be.

Well the ambient inside the case is now 49C. And I read that from 25C to 70C, the PSU output max wattage reduces from full to zero! So I really have a 150 watt supply running 2 athlons, 3 256MB graphics cards, and 2 250GB drives.


--
13 parrots and rising http://www.petersparrots.com
93 silly video clips http://www.insanevideoclips.com
1259 digital photos http://www.petersphotos.com
Served from a quad watercooled dual 2.8GHz silent Athlon with a half terrabyte Raid.

Condoms aren't completely safe. A friend of mine was wearing one and got hit by a bus.

 

[Dave]

Archived from groups: alt.comp.hardware.overclocking (More info?)

"Peter Hucker" <hucker@clara.co.uk> wrote in message
news😱psaioropgaiowgp@blue...
> I always thought over 10% out on a voltage was a problem. MY PSU (300
watt) > is just over 10% on occasion (the -5V line). Will this break
anything?

What did you measure it with, the BIOS info? Don't rely on that as they are
not all that accurate, get hold of a DMM (digital multimeter) and measure
the voltage.

My BIOS readings caused me a little concern until I used my DMM to measure
the voltages. I don't worry anymore.

Dave

 

[Guest]

Archived from groups: alt.comp.hardware.overclocking (More info?)

On Sat, 03 Jul 2004 13:07:45 GMT, Dave <dave@hotmail.com> wrote:

>
> "Peter Hucker" <hucker@clara.co.uk> wrote in message
> news😱psaioropgaiowgp@blue...
>> I always thought over 10% out on a voltage was a problem. MY PSU (300
> watt) > is just over 10% on occasion (the -5V line). Will this break
> anything?
>
> What did you measure it with, the BIOS info? Don't rely on that as they are
> not all that accurate, get hold of a DMM (digital multimeter) and measure
> the voltage.
>
> My BIOS readings caused me a little concern until I used my DMM to measure
> the voltages. I don't worry anymore.

Please smack me about the head - I forgot all about that.

[scuttles off to get £100 meter]

Well...... The 5 volt is really 4.98, not 4.7 as the board says 🙂
But the 12 volt is 12.48 not 12.12 as the board says (still only 4% over though)
The -5 volt is in fact correct at -5.56. Shall I just ignore this as it's for ISA? (I think?) Could it be out due to zero load? I know switched modes are freaky with no load, but I thought it was no TOTAL load.

PHEW that is hot in there. I don't have a water cooler on the northbridge yet, and there are 3 radeons giving off heat too. Perhaps some vent holes in the top of the (lieing down) tower case?

--
13 parrots and rising http://www.petersparrots.com
93 silly video clips http://www.insanevideoclips.com
1259 digital photos http://www.petersphotos.com
Served from a quad watercooled dual 2.8GHz silent Athlon with a half terrabyte Raid.

Someday we'll look back on all this and plough into a parked car.