I have a problem with my PC restarting while playing games. Sometimes it happens 15 mins into a game and sometimes two hours in. It happens more in some games than others, particularly GTA IV and Fallout New Vegas. The system remains stable while not playing a game. My setup is listed below;
M4A78-EM mobo flashed BIOS to support Phenom II
420 Watt Antec PSU
Phenom II 965
HIS Radeon 6870
4 GB Ram
I think it may be a power problem. I ran prime 95 for CPU a half hour, the system was stable with CPU heating up to 60C. I also ran a FurMark for GPU for 20 mins, it topped at 83C remained stable. In any game, the temps reach a maximum of 75C, according to GPU-Z, so I have a hard time believing it's a heat issue. While the system remained stable during each stress test, while playing a game both CPU and GPU are working hard, so maybe it's this combination that causes a restart.
Am I completely off? If anyone has experienced something similar and fixed it, please reply.
your 420w psu is not enough. http://www.antec.com/specs/rm420_spe.html that is the only 420w psu antec make, and it only has 18A on the 12v rail. go buy yourself a new psu with at least 35a on the 12v rail.