I'm having some serious trouble diagnosing an issue that I've been having with a box I built a couple of months ago.
Here's the hardware: newegg wish list
After playing a game for 30-60 mins. The whole computer freezes (crashes?). It just stays stuck on the screen and is completely unresponsive. The only thing I can do is shut it down by holding the power button for a few seconds. I can replicate this more quickly by running Furmark for 3-5mins. Never a BSOD, just completely frozen.
Troubleshooting so far: I've had the issue under two separate XP installs and Win7 Pro with different driver version. (I have Arch Linux installed too. It's never had the problem, but I don't play games there.)
At first I assumed that it had to do with heat. I've monitored both the CPU and graphics card temps. I don't think it has anything to do with the CPU because I can run prime95 for at least a couple hours without any problems (haven't tried longer). And I've been able to cause it to freeze under Furmark with the GPU temps ranging from 59C to 80C, so it doesn't seem like heat there either.
Initially I did have the fourth core of the proc unlocked through the BIOS, but everything has since been returned to the stock defaults.
Finally I decided it must be a problem with the graphics card, so it's been RMA'd. In the meantime I'm using an ATI 6750. It has the same problem! So there probably wasn't anything wrong with the other card.
Does anyone have any ideas? Or suggestions? Let me know if I've left out any relevant details.
UPDATE 1: Memtest Passed
UPDATE 2: Computer doesn't freeze with the side of the case removed.
If it's not the graphics card, RAM, CPU, or HDD, and it does seem related to heat, that leaves only the motherboard. Does this kind of thing happen when a motherboard overheats? Is there a specific sensor that I can monitor?
UPDATE 3: I have been using the computer with the side of the case removed for a while and I've yet to have it freeze again. Although I can't use it that way forever. I'm fine with further upgrading the cooling system, but first I need to pinpoint what's overheating. Any suggestions? PLEASE?
UPDATE 4: A couple of weeks ago (before the new graphics card) I was able to take a picture of the temps after it froze. Although it is a camera phone pic, so it's not the best quality.
There are two things that I think might be relevant. First the VIN1 voltage shows a ridiculously large max. However, this doesn't happen every time it freezes and I've seen it report that number when it hasn't frozen. The other strange thing is that under the fans section, there are three fans that always appear right before it freezes. Under normal conditions the fans section only has one entry (CPUFANIN0).
UPDATE 5: I posted this in a comment "The case actually came with two 120mm fans, both of them pointing inward (intake). I replaced those fans with better ones. I also switched the rear fan to point out as an exhaust. Neither seemed to help."