recently I got a GB 7850 OC and a SS-520GB to power it up. http://i.imgur.com/TFS3j.jpg?1 ; http://i.imgur.com/hb4Pu.jpg this is my rig.
I loaded Fallout 3 and the game freezes in the first few mins, GPU and PSU not overheating, GPU never got over 50C. Same thing happens with CIV 5, I load a game play a few turns and it suddenly freeze. Before the freeze the games are running smoothly.
Some like LoL or Dota2 don't freeze tho, so I'm not really sure what's the problem. GPU, PSU, memory?!?
Possibly due to gpu, and memory but as only the game freezes not the system I'd have to say that it is due to some gpu driver error try updating them and also make sure that every other prerequisite drivers are installed for the game. Try reinstalling them.
Try to run more heavier games like crysis 2, if there is no problem then it just be due to some driver error.
Reply to Xttony
December 1, 2012 12:22:35 PM
Update drivers, update BIOS for both GPU and motherboard, re-seat hardware components (especially the GPU) and check all connections inside and outside the case.
Your PSU meets the minimum requirements so it should fine. There is a possibility it could be faulty but I doubt it.