okay, figures since physx running on the cpu is quite ancient when it comes to CPU instructions used, and mostly single threaded(both things your i7 does alot better). david kanter wrote a nice piece on the subject a while back at realworldtech iirc. Anyhow, then it would seem like there is something else the matter indeed! Have you got the right version of physx software? Seems like if you install the newest version physx can also run on your cpu, which it wont with only the physx version provided with the game. You might want to try downgrading your physx software to the version that came with the game.