Ok now I found this in the general discussion forum and since it worked for me I thought I would post it here. I was having lack-luster performance in game and I shouldn't because of its SLI capacity. Anyways after combing the forums and tryin the nhancer crysis profile fix that still didn't quite nail it, I found a fix so simple that I wanted to hit myself.

No guarantees for everyone that this will work but it worked on my sli'd gtx260's

1) make sure you have 196.21

2) right click your desktop and go to nvidia control panel and then find the profiles.

3) create one for napoleon.exe (its under steam apps, common)

4) in the profile set sli performance mode to force alternate frame rendering 2

5) enjoy the game

If this didn't work for you I apologize but it did for me and my performance has doubled. Tested it with a massive battle (all settings ultra, everything checked, full AA etc, etc, at 1680x1050) and did not have a single hitch.

I got this from forum member Shabby_Ronin so thank him if it works for you.