Holding at 40 fps should get you a smooth gaming experience, not sure what you mean by keeping up, you won't notice a difference if its 40 or 140 fps. I ran that game max on a FX-60 @2.8 and 3870 at 1680x1050 smooth (no AA didn't need to), still thinking something is a miss here. Unless its just that your server cpu just doesn't like to game then sell it and buy a 930 or something. Could at least give overclocking a try first.