Epic fail on my part or I have a gimp card. I ran 750MHz and it sometimes crashes on Diablo 3 sigh. Upped the voltage to 988 from factory stock of 975 and it still crashed. I reset everything back to stock and it's fine. I figured anything up to 800MHz would be pretty safe at stock voltage. Temps are at 66C for stock setting during gameplay. I am going to try raising it in increments of 10MHz tonight and see what it does. Anything else I could be doing wrong or could be looking at? Phenom 2 X4 BE, 8GB memory, and 750W Corsair power supply running on XP 64bit.
Edit: Galaxy GTX 560 Ti 448 card.