Well, my outdated PC handles it fine with things set to mostly very high. If you looked at my vids, you can see the frame rate is smooth:
http://www.stage6.com/user/xman11/vi...down-in-Crysis
Anyway, the best guide I have found is this one:
http://www.tweakguides.com/Crysis_1.html
Hope it helps. I'll get back to making new vids after a while. I don't want to spoil the story before people get a chance to play it.
-S