I believe my symptoms are consistent with a power supply that is not powerful enough:

My computer is housed in a cheap, dinky case that came shipped with a cheap, dinky power supply. (300W, i believe) I own an Athlon XP 2400 processor and a Radeon 9700 pro. Correct me if I am wrong, but both of these are notoriously power-hungry. (The processor I know is power-hungry and is not found in laptops, and the video card requires a direct connection with the power supply to draw enough current.) Whenever I am playing pretty hefty video games (UT2004) on my linux machine, the computer will spontaneously freeze with no warning or provocation. I've checked the bug lists and my problem does not appear. When I go into the BIOS and check the voltage levels, most levels are very close to safe limits, and the -12 voltage is well beyond safe limits. (Around -13.1V, and is only rated for 0.5 amps) I'm no expert, but I believe my power supply is not powerful enough. I would like your opinion so I don't purchase an expensive piece of hardware pointlessly.

It sounds more like an overheating problem than lack of power.

Usually when you run over a PSU limit, it cuts out, and the computer loses power. I have seen this happen quite a few times, and once or twice because of a video card.

I would check the internal temperature of your machine to make sure it is within safe limits. If it is high you should add more case fans, and a PCI fan blowing right over the video card. If you have a serious heat problem, you might even look into getting a video card cooler.

Always buying a better power supply will give you better stability although you have to be carefull not to budge anything in the computer case when installing a new power supply.

-13.1 VDC (Voltage DC) is way over its regulation limit for -12 VDC. Buying a new power supply is a must if you want a few years out of your system.

Replacing the power supply you may not have to do anything to the cooling of the system. Like what MS3FGX said, check the internal temperature just in case. You can either add more fans or use water cooling for the hot devices like the CPU and video card.

My 2 cents - I agree it seems more likely to be a thermal problem than a power problem. Do you have something like gkrellm installed, and if so, what temperature is your CPU hitting? -- J.W.

That is a Overheating issue...one of the things I would do is just like J.W said install gkrellm and see what temp you system is hitting and also got in to you bios and check you PC Health Status while system is running at Idle for a few mins to see what the max temp it hits just sitting Idle... then just add some better fans to cool it down.

The other thing that can help is if you have it under your desk maybe bring it out from under the desk, either on top of you desk or on the side of your desk, this helps in not having the computer recycle the same hot air that is traped under your desk. Hope this helps

Gkrellm and BIOS both agree. My processor idles at about 54 degrees Celsius. It is sitting on top of a desk, so I think it is getting fresh air. Is 54 really quite hot? That's about 130 F. Is there a way to check the VPU temp? It runs a fan, but it might not be running at the right speed.

That seems pretty darn hot to me. My Athlon usually runs at about 42 or 43 Celsius, which is about 109 or 112 F. Are you overclocking it? That definitely could be another factor in your sudden lockups, and if so, I'd suggest stepping the speed back down to its normal range, and seeing if that makes a difference. -- J.W.

That is way too hot for a computer at idle.

I live in hot, sunny India and the ambient temperature is around 38 Celcius almost always...

My CPU temperature regularly touches 80 Celcius (Phew!)... I have four fans whirring inside the case, but nothing seems to bring down the temperature below 65-70 Celcius. I also have had these random crashes and freezes in my comp. The problem is, what can I do? I don't seem to be able to find any solution to the problem.

Like the other forum members here, my -12VDC also is almost always at -12.9V or -13.1V.

If your system is that hot, your next step would be to look into liquid cooling.

Ouch!! That's approx 175 degrees -- I'm amazed that your PC runs without major issues. I'd suggest adding as many fans as you possibly can. Similarly, if you are OC'ing, step it down. -- J.W.

Aha! I'm underclocking, in fact and that just steps down the temperature by 5 or 7 Celcius...

EDIT: By the way, I forgot my specs: ASUS A7v8X-X with Athlon XP 2600+ running at 1667 MHz instead of the full speed of 2083 MHz. (Currently the system is in a state of dissassembly as my motherboard has some problems and I have given it for service to my dealer)