Ray, thanks for the explanation. After about an hour of testing, disabling Shared Memory did not stop the stutters. In fact, disabling Shared Memory caused my card not to be overclocked, as set in the game profile, when started and actually overclocked the card after quiting the game. If it's any consolation, the stuttering does not occur in all games like Crysis or Stalker. But it does stutter in all UT3 and games that use this engine. I hope you can fix this because a lot of cool games are coming out like Turok that uses the UT3 engine. I like the UT3 engine because it is the only engine that uses both cores of my FX-60 100% of the time. So for now, ATT Shared Memory enabled and all OSD off. Result is games run silky smooth and top notch. Cheers to you for all of your time.