Recently I've been having problems with what I thought was my GPU, but when I submitted an RMA and sent back my card, I got it back saying there was nothing wrong.
My problem is, that when under load (in my case BF3 or FurMark, at about 70C from what i could tell in FurMark) my system just freezes and refuses to do anything unless I restart on the case. Another thing is, when watching shows on Netflix or in VLC etc. I get the sound stutter only.
Since the store from where I bought my GPU said it was not the problem, I now tried running with one memory-block at a time, and still the same problem.
My setup is:
i5-2500K @3.3GHz (was overclocked @4.6GHz but not anymore)
GTX670 ASUS double-fan
Corsair 1050W PSU
ASUS Maximus IV Extreme motherboard
4x2GB Dominator 1333MHz RAM 7-7-7-20 (if that means anything)
+ SSD and HDDS
I'd say my case is properly ventilated and I have a Corsair H100 on my CPU.