Thank you very much for your efforts guys. I see you guys don't use V-Sync. I must say I don't know how you can drive without In other games, it never has been a problem since the stuttering is so light that didn't notice it while driving/flying. But in rF2, at least on my side, there is much more stuttering than in other games and it really kills the immersion for me. But it seems I'll have to live with it. I deactivated V-Sync and went to 120 fps. I must admit that the stuttering effect itself seems to be lighter but still present, and the tearing and other negative effects introduced by the unsynchronised images are so horrible that I can definitely not play this way, sorry @ Butch I know that it's a matter of preferences and that people have not the same perception of smoothness, but I can assure you that with V-Sync off, the game can not be smooth. It's technically impossible since the images sent by the GC are not synchronised with the refresh rate of the monitor. Even with 300 fps, it will never be smooth (but maybe you perceive it smooth). And I don't even talk about tearing. Try just once to activate V-Sync and you will see a huge difference. It's incredible how immersive it gets with V-Sync on. Principally the movements of other cars around you. It's just "real" ! I can't play any game without it. And about input lag, it's there but hardly noticeable, and I did hours of tests and I can say that in my case, my lap times are exactly the same with or without V-Sync (maybe because I'm not an alien ?). It is not a coincidence that nVidia puts so much efforts to optimise the V-Sync technology, with "adaptive V-Sync" first and with "G-Sync ready monitors" next year (I can't wait for that). It brings such an improvement in immersion !! As a conclusion, I now know that the TrackIR stuttering problem exists for everyone, but not everyone will notice it and I don't know if there is a solution to eliminate this effect. I'll have to try another tracking system to see if the problem comes from Naturalpoint's technology/drivers. Thank you very much to all of you that replied.