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A7N8X-E Deluxe and PSU voltage

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Anonymous
a b V Motherboard
February 12, 2005 4:32:24 PM

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Hi,

I think I have a problem with my PSU.

I have a XP3000+ unlocked, running fine at 11x200Mhz (XP3200) with
1,675 Vcore.
It pass 6 hours af prime95.
So I think my RAM is OK at 200Mhz (Samsung PC3200) and the CPU could go
higher.
But MMB5 notice a great loss on the +5v while burning.
It start from 4,95v idle, drops to 4,81 while in prime95 burning, then
go back to 4,95v at idle.
I took a digital multimeter on the +5V off the mainboard connector (the
gray one), and it also show a loss while the prime95 is running. During
the burn, the others +5v on the PSU stays at 5.03v.

But if I try something like 11.5x200, the the main +5v falls to
something 4,75v
I suspect the PSU not enought for 'oc

The PSU (labelised 450W) shows :
DC 12v 17A
DC 5v 18A
DC 3.3 16A
DC 5VSB 2A
DC -5v 0,5A
DC -12v 0,5A
(350W)

Can somebody confirm, that PSU could be the bottleneck and changing it
will help me to go higher in frequency.

Could I try to grab some extra amps on a +5v (on a unused molex by
example) and "Y" it to the main connector?

--
Alni
February 12, 2005 4:32:25 PM

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <mn.632c7d5225d55dfe.22859@nowhere.com>, Alni
<none@nowhere.com> wrote:

> Hi,
>
> I think I have a problem with my PSU.
>
> I have a XP3000+ unlocked, running fine at 11x200Mhz (XP3200) with
> 1,675 Vcore.
> It pass 6 hours af prime95.
> So I think my RAM is OK at 200Mhz (Samsung PC3200) and the CPU could go
> higher.
> But MMB5 notice a great loss on the +5v while burning.
> It start from 4,95v idle, drops to 4,81 while in prime95 burning, then
> go back to 4,95v at idle.
> I took a digital multimeter on the +5V off the mainboard connector (the
> gray one), and it also show a loss while the prime95 is running. During
> the burn, the others +5v on the PSU stays at 5.03v.
>
> But if I try something like 11.5x200, the the main +5v falls to
> something 4,75v
> I suspect the PSU not enought for 'oc
>
> The PSU (labelised 450W) shows :
> DC 12v 17A
> DC 5v 18A
> DC 3.3 16A
> DC 5VSB 2A
> DC -5v 0,5A
> DC -12v 0,5A
> (350W)
>
> Can somebody confirm, that PSU could be the bottleneck and changing it
> will help me to go higher in frequency.
>
> Could I try to grab some extra amps on a +5v (on a unused molex by
> example) and "Y" it to the main connector?

I've measured the current on my A7N8X-E, and using Prime95 the
computer is drawing 16.6 amps from +5V just to run the motherboard.
Disk drives need 1 amp on +5V. Your _total_ output rating is
18 amps for +5V, and if you have a decent video card, there
simply is not enough current available on your power supply.
(A 9800pro draws 5 amps on +5V while gaming.)

You will notice that your power supply has a label "450W",
but what really counts in this case (building an AthlonXP
computer) is to have lots of amps on +5V.

Here are some sample Antec Truepower output numbers:

VOLTAGE +12V +5V +3.3V -5V -12V +5VSB

TRUE330 17A 30A 28A 0.5A 1.0A 2.0A
TRUE380 18A 35A 28A 0.5A 1.0A 2.0A
TRUE430 20A 36A 28A 0.5A 1.0A 2.0A
TRUE480 22A 38A 30A 1.5A 1.0A 2.0A
TRUE550 24A 40A 32A 0.5A 1.0A 2.0A

Notice how even the 330W power supply has 30 amps of +5V
available. That is enough to power an AthlonXP 3200+ and
a high end video card.

So, before you buy a new power supply, check the "amps"
instead of the "watts".

As for going higher in frequency, I was able to overclock
my system above 200x11, but the gains in actual use were so
small, that I returned the settings back to 200x11. That is
equivalent to a 3200+.

HTH,
Paul
February 12, 2005 6:32:38 PM

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Alni wrote:

> Hi,
>
> I think I have a problem with my PSU.
>
> I have a XP3000+ unlocked, running fine at 11x200Mhz (XP3200) with
> 1,675 Vcore.
> It pass 6 hours af prime95.
> So I think my RAM is OK at 200Mhz (Samsung PC3200) and the CPU could
> go higher.
> But MMB5 notice a great loss on the +5v while burning.
> It start from 4,95v idle, drops to 4,81 while in prime95 burning, then
> go back to 4,95v at idle.
> I took a digital multimeter on the +5V off the mainboard connector
> (the gray one), and it also show a loss while the prime95 is running.
> During the burn, the others +5v on the PSU stays at 5.03v.
>
> But if I try something like 11.5x200, the the main +5v falls to
> something 4,75v
> I suspect the PSU not enought for 'oc
>
> The PSU (labelised 450W) shows :
> DC 12v 17A
> DC 5v 18A
> DC 3.3 16A
> DC 5VSB 2A
> DC -5v 0,5A
> DC -12v 0,5A
> (350W)
>
> Can somebody confirm, that PSU could be the bottleneck and changing it
> will help me to go higher in frequency.
>
> Could I try to grab some extra amps on a +5v (on a unused molex by
> example) and "Y" it to the main connector?
>
Alni,
Your PS could definitely be one problem. For an AMD system I'd look for
a PS that would give me upwards of 30A on the +5v and near 30A on the
3.3v. Depending on the peripherals you have, 17A for the 12v, as well
as the other readings, are probably OK. Will this help with OC'ing?
Maybe, but if your XP3000 is a Barton core, it is designed to run at
333FSB (166mhz x13 I think), so your getting a bit of an OC already with
200 x 11. Going higher might need a little bump in Vcore and/or Vdimm
and more Cooling in addition to a beefier PS! A 4.75v reading is
within spec, albeit at the low end, as most PS have a tolerance of +/-
5%. Getting a good quality PS and keeping the one you have for a
backup, in case of failure, is not a bad idea either. They tend to have
a higher failure rate than most of the other components! As far as
making a "Y" connection with the PS you have, I don't think that will
buy you a thing. YMMV.
Rob
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Anonymous
a b V Motherboard
February 12, 2005 7:50:06 PM

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Bonjour,

Alni a présenté l'énoncé suivant :
> Hi,
>
> I think I have a problem with my PSU.

Thanks everyone !

I will bought a new PSU checked to have 30A on 5v and 3.3v

--
Alni
Anonymous
a b V Motherboard
February 12, 2005 7:51:31 PM

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Alni wrote:
> Hi,
>
> I think I have a problem with my PSU.
>
> I have a XP3000+ unlocked, running fine at 11x200Mhz (XP3200) with
> 1,675 Vcore.
> It pass 6 hours af prime95.
> So I think my RAM is OK at 200Mhz (Samsung PC3200) and the CPU could
> go higher.
> But MMB5 notice a great loss on the +5v while burning.
> It start from 4,95v idle, drops to 4,81 while in prime95 burning, then
> go back to 4,95v at idle.
> I took a digital multimeter on the +5V off the mainboard connector
> (the gray one), and it also show a loss while the prime95 is running.
> During the burn, the others +5v on the PSU stays at 5.03v.
>
> Can somebody confirm, that PSU could be the bottleneck and changing it
> will help me to go higher in frequency.

If your voltages drop under load, then the PSU is faulty or run outside of
spec. You need to replace it with a better one.

> Could I try to grab some extra amps on a +5v (on a unused molex by
> example) and "Y" it to the main connector?


Probably not wise.

Ben
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