PSU question

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I'm experiencing instabilities with my PC. There are
lock-ups and hard-resets in 3D-games, even if the box is
not under heavy load. The temperatures are very low. The GPU
is below 50C and the CPU-cores are all under 40, sometimes even
under 35C.

I have hooked up the following periphery to my
460W Enermax PSU:

Q6600 currently at stock 2.4 GHz
XFX GeForce 8800 GTS 640MB at stock 514MHz
4x250 GB harddisks, two Samsungs and two Seagates
1 DVD-ROM and 1 DVD-RW, both NEC
A 12V water-pump
2 fans
and 2GB DDR2-800 RAM

Is this too much for the PSU, or could something else be
the cause for the instabilities?

It could just as well be a Direct-X or a Driver-problem, or

Thanks for your time!

Daniel Albuschat

Re: PSU question

If the crashes are happening regardless of load, check the obvious
suspects first: reseat your cpu and memory, video & pci cards,
check cabling etc.

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Re: PSU question

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    That should be fine. I asked because I have seen that different
programs, especially games, may react differently to memory running too far
out of spec and cause lockups and even reboots. I have also found this with
the processor OCing too. Sometimes just a small (50-100mhz) drop in the CPU
speed can clear up intermitten issues with some games. I am more into
simulations and have run into this several times when every stability test
and bench would run great, but one sim may exhibit problems. Adding just a
tad of vcore or just backing down the processor just a little has fixed the
problem in several instances. It is all part of the overclocking


Re: PSU question

Daniel Albuschat wrote:
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12V2 is 20A, processor draws 10A max from this rail (assuming a B3 stepping
12V2 9A + 4*0.6 + 1*1.5 + pump + 0.5A < 22A,
      13.4A + pump < 22A , pump < 7.5A
      (note - assumes one optical drive has media in it)

Without knowing the type of pump, it is hard to guess whether
that relationship is met.

Total load on the PSU is roughly 370W plus pump_watts, or 80%+ of capacity.
( 12 * 23.4 + 4*5 + 2*7.5 + 50 + pump )

I believe it is possible in Windows, to limit the number of cores
used by the OS and applications. You might try dropping down to one
core, and then running some version of 3DMark as a test. (Using only
one core would help limit the CPU heating, while the video card is
tested, and also eliminates a multi-core software issue.) It could be
this is related to the video card.

You can also run memtest86+ on your 2GB of RAM.

I'd also disconnect the hard drives, boot a Knoppix or Ubuntu liveCD,
go to and get a copy of Prime95. As long as you make copies
of the directory with the executable in it, it is possible to run multiple
copies of the Prime95 torture test. The torture test checks memory and
processor integrity at the same time. The video card should be in a
relatively low power state, and less likely to fall over. (Each copy of
Prime95 will need the memory allocation set, and I'd give each copy
slightly less than 1/4 of the free memory at the time.)

So there are some test cases you can run, and they'll help pinpoint
a potential source of the problem.

If you don't have Knoppix or Ubuntu, you can also try Orthos in Windows.
This is better than nothing, and runs the Prime95 test code. This
will give you a quick answer on CPU/memory stability.


Re: PSU question

Paul schrieb:
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Hello Paul, thanks for your detailed answer!

Yes, that's about the same as I calculated.

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I haven't experienced any problems with 3D Marking, anyways.

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Did that. Well, I was too lazy to look for my memtest CD so I used
Vista's memtest utility. I have both XP and Vista installed, but I'm
using XP mainly.

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I tried that first without disconnecting drives and booting into Knoppix
so I'd know that it does cause the troubles I'm trying to eliminate.

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Or just download it. :-)
I fact, I only have a 'original' Knoppix DVD that was handed out at the

Well, from what I've experienced I might conclude that this is a
software (driver) issue, not a hardware-issue. It's not caused by load
itself, but probably by handly of individual games/applications.

I already have the latest nForce and Geforce drivers installed, so I
might just wait for new ones to arrive.

I could try playing CoD in Vista, too, to see if it crashes there.
In fact, I'll do that right now. :-)

Thanks again for your in-depth answer,

Daniel Albuschat

Re: PSU question

Daniel Albuschat schrieb:
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Okay, it's definitely a driver issue. I could play through the whole
game in Vista without issues.
That's too bad, since I have quite a few frames less in Vista than
in XP. :-(

Daniel Albuschat

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