i am no expert but i would say the grahics card (mine is new gtx 560 2GB 3 days old) is overheating, something to do with coding i think, either the game or drivers for the card.
WHAT I DID DO IS TURN UP THE FAN SPEED JUST FOR THIS GAME AND JUST PLAYED 1 HOUR WITH NO CRASHES (SPEED SET FROM DEFAULT TO 65% JUST TO TRY) A BIT NOISEY BUT I ENJOYED MY FIRST WHOLE HOUR OF EXPLORING...
i hope nvidia or bethesda solve this problem soon i look forward to many months playing and exploring we just need to give them a bit of time as everyones PC is different.
Oh yes and all at max setting with 45 - 55 fps.
AMD 1090 8 6
GTX 560 2gb
12gb ram
