Just skimmed through this thread so apologies if you've already tried this but try a single graphics card in slot 2 instead of slot 1. Might be that both cards are fine but a PCI-E slot is damaged somehow.
I just tried that, and whilst it doesn't appear to to be the problem, it did help me figure out when and how games are crashing.
Then you will be pleased to know that I have figured out exactly how this is happening!
I just need you guys to tell me why its happening!
Check this picture out:
I just ran an auto tune test on one card in the lowest PCI slot thinking that maybe its actually the PCI slot thats broke, since I only ever put the cards in that slot to test.
Now, sadly the crash still happened but this made me realise exactly what is happening.
The auto-tune managed to get the "High Performance GPU clock settings" sorted, and plonked them at 690 MHz.
Sorted.
It then started to work through the "High Performance memory clock settings", it got to 998 then the crash occured.
So it would appear that I can now simulate the crash. If I put my settings up to full wack and hit "test custome clocks" the crash occurs. Now I hadn't been using Graphics overdrive at all, I thought that maybe it was this what was causing the crash, and turned them off. But if I turn off Graphics Overdrive can the Graphics card still go higher than 993 MHz at default settings?
So it appears the problem is the card. I just need to figure out if I can stop it going passed 993.
I think.