As stated by Netweaver, vsync has nothing to do with stuttering and lag. The default refresh rate is 60hz, IIRC. 60hz = 60fps = smooth as butter. The human eye, TRAINED OR NOT, cannot see the difference between 60fps or 61fps, or 6000fps. Even if you manage to alter vsync on the N9, there won't be any difference, other than screen tearing, assuming it can render everything beyond 60fps.