Don't have time to run the test right now, but I'm pretty sure I know what is causing the stuttering on my game. Keep in mind, my PC is new, it can run Crysis, Far cry 2, call of duty 4 etc. with the highest graphics settings. On AH I have AA on max, 1024 texture, and all of the graphic settings maxed out except for smooth shadow, and I get 60 FR. When I turn on smooth shadow, my FR drop to 45 and I get stuttering. So I'm willing to bet that smooth shadow is causing some problems...