I use an GTX 670 Top from Asus and the latest beta driver what comes new from nvidia and get bad performance with fps drops.
It feels like stuttering and lag dont tried 310.61 maybe its better and maybe someone can tell me what driver works better for gtx 670.
40 Fps were ok but i dont get stable fps without any lag, i heard that a patch is coming and is the issue for bad performance i dont test the game at release only
6 hours after.
Try these: http://www.geforce.com/drivers/results/53348
Supposed to improve performance for 680GTX but might help you as well.
im using the latest beta driver like i said 310.64 im not sure if i get fps drops because it feels like stuttering and lag i capped it now with vsync at 30 fps but it doesnt change. And now i get black screen crash maybe i should flash my bios AC3 crashes at same black screen as Far Cry 3 and Asus said at high clocks the gtx 670 crashes. It looks like black loading screen and then only deep black screen confusing