PC random shutdown

Hello,

I have built a pc 2 years ago and everything was fine until I upgraded my GPU and RAM. I upgraded my GPU to a gtx 680 and added 8 gigs of Ram. Ever since then my computer would start freezing or shutdown and restart immediately after an hour or two of play. This would only happen on games like battlefield 3 and GTA 4. At first it would shut down on its own and restart immediately. I took out the 2 gigs of RAM I added an now its freezing. I've have checked my temps on my CPU, 50C and GPU 65C when playing games. I don't think its a temp issue. I've read online that is could be a psu issue or a motherboard, but I can't get a clear idea. I've also checked windows crash dump, noting and RAM diagnostics and they were fine.

Here are the specs:

  • Motherboard Asus IP8Z68-v PRO Z68 LGA 1155 
  • Gigabyte GTX 680 OC 2GB GDDR5 Express 3.0 
  • PSU Cosair CMPSU 650W
  • CPU i7 2600 3.4 GHz 
  • Ram 2 4Gig G.SKill Ripjaws DDR3 1600

any ideas 

Thanks

Sounds like the PSU might be the problem. If you can, try to hook it up on a friend's PC and see if the same thing happens.

EDIT: updating the BIOS could fix this problem too.

I will try that thank you