Possible problem caused by PSU

[JmactheAttack]

Hello,

I'm trying to troubleshoot my graphic card problems.

750W Corsair PSU
12GB Corsair DDR3 Trichannel
Intel Core i7 920 2.667GHz
4x SATA HDD's
2x Blu-ray / DVD+-RW Readers
ASUS P6T Mobo
6x Chassis fans
& 2x BFG NVIDIA 285GTX 1GB OCX cards (SLI'd together)

The basic gist of the problem is that whenever I try to play a game (mostly Modern Warfare 2 BUT not just that) at full 1920x1080 with any anti-aliasing, my computer will run it fine, but after probably an hour of gaming, it starts to bug out and have very strange issues. One thing that has seemed to be a common theme is that normally afterwords, I get what looks like to be dead pixels on my screen, but they move and are clearly something with the graphics card.

Over the last week I've been running just off of one card and I removed the other one entirely. So far it's been running flawlessly.

Any thoughts on whether this may or may not be caused by a shortage of power to the cards?

 

[eddieck]

I'm curious what the TDP is on those GTX 285 OCX models. The stock 285 is 183W and two of those should be fine on your PSU (though perhaps cutting it slightly close at full load). Can you downclock to stock and see if the issues persist?

 

[JmactheAttack]

I don't believe downclocking is possible

 

[blivit4]

This sounds more like a heat problem. It could be the GPU, the VRMs on the video card, or a combination of the two. I would get and run a copy of Furmark, which will load the video card more than any game can, and see how long it takes for the video to crash. If it crashes right away, then it's a PS problem. If it takes several minutes then it's a heat problem.

You have to know what you're trying to fix before you can fix it.