I installed diablo 3 on pc (1920x1080), in the middle of game I got graphical corruption and then a message on monitor : VGA No signal. After waiting a few seconds, display came back but it was REALLY laggy even on desktop. It scared me as hell and i immediately pushed reset button. Now it is perfect. I'm using seasonic m12II 620w psu, e8400, p5q deluxe, 8800gt and 2x2 1066 corsair dominator.
I have never tried overclocking before, even the cpu. What causes this ?
it means your drives has crashed and recovered with safe clocks ( thats why you got very low fps). if you run msi afterburner with on screen display options to show you the gpu/ memory speeds you will notice how the clocks will be reduced after drivers crash (i think its some sort of safety feature). next time when you get a driver crash simply close the game and restart your system. you dont have to do a cold restart because your pc is still usable and you can get corrupted files by turning the pc off without notice
make sure you have the newest drivers and that your card is not overclocked