nVidia performance tip using old firmware.

[driftefx]

I am currently using 181.71 drivers. I noticed certain games were choppy compared to the 190.62's in single screen mode. I decided to update my SLI profile and the physx drivers seperately. They run much much better now.

http://www.nvidia.com/object/nvidia_multigpu_SLI_profile_update_v2.html
http://www.nvidia.com/object/physx_9.09.0814.html

Check it out and see if that helps.