I just built a computer and I was able to install Windows 8.1 and all drivers without a problem. For some reason though, whenever I stress the video card or play a game, the computer will restart with no errors or crash reports other than the computer did not shut down properly. I've tried everything from updating all the drivers and updating the bios. I still am having this issue and I don't know what to do. Thanks for any help.
Barring any heat related failure, I'd suggest that the PSU is the culprit. Sounds like loss of power, the scary thing about a faulty PSU being a possibility is that there's no real telling what damage may have been done to the system if that's what really is the root of the problem.
Figured it out...it is the PSU, I underclocked the video card so it doesn't draw more than 1.1V and it hasn't crashed. As soon as I allow it to hit 1.2-1.25V it resets. Thanks for the help.
Tried that with 2 of the unused rails. ~40A I just checked the GPU box and in fine print at the bottom it recommends a 500W PSU which I had but with a 12V rail producing a minimum of 48A