Whilst the driver may fix the issue it may not. The game is having optimisation issues at the moment. If you check the MyCrysis forums you will see many people are suffering erratic FPS. Gtx 670,680 even 690 and 6970/7970 all types of cards, even when playing lowest settings are suffering.
Take me for example:
GTX 570 1.25GB
average fps = 40.. lots of times dips to 20s with lowest settings and everything.
Others are having similar problems. As i said, optimisation. Should be fixed soon.
Here, take a look... there are some options you can do to increase your FPS if your driver installation doesnt work: http://secure.mycrysis.com/forums/viewtopic.php?f=65&t=59554