I believe the stuttering is caused by the Vsync option

[blake123]

No, it's not a bug. That's how vsync works. Vsync works at 30,60 or 120 fps. In order to keep the video synchronized it must be at these three fps. So if you enable it but the game goes to 55 for example it will make it 30. If the game went to 69 then you would get 60.

Nvidia has a feature called adaptive vsync which enables "custom fps" with vsync enabled.

Well, I have ATi, and I know programs like RadeonPro won't work because the game is OpenGL based