http://www.youtube.com/watch?feature=player_embedded&v=tEHoD9FBauM
You've got your answer I think. Keep in mind that it's a 660 (not the 660ti) in the video.
You should be fine with Physx high then.
That was a 660, not a 660ti.
soooo stupid
Why would anyone think that this physx stuff would matter to me?