At least I have no issues with the GTS 640 on my other computer lol. I do get a higher fps on the 8800GT though, but I'm just upset about this, I just pray it's just a driver issue. I was reading in another forum some1 else had the same problem with a evga superclocked, and a BFG OC, tried both!!. If it's happening on different brands, I'm guessing it is possible it could be just a driver issue. People are saying when the GPU is hitting 71C it freezes into a loop on the card, and then freezes.
I dunno, I'm just babbling lol. I'll just keep some faith that a driver will fix my problem and many many others.