IF you have 0 max frames ahead your GPU will not prepare frames before they are displayed, causing less stress in the GPU but as a consequence the game will stutter a bit and decrease mouse lag since you have more frames because there is less stress on the GPU. The more max frames you pur, for example 3, before the frames are displayed, the GPU is already calculating the 3 frames ahead, making the game run "smoother" less stutter but at lower FPS and increasing mouse input lag. You can read the rest of this post at if you need more explanations Source: http://forums.guru3d.com/showthread.php?t=143811 EDIT : forgot this, - Max Frames to Render ahead only applies when V-Sync is OFF. When V-sync is on, then double-buffering or triple-buffering are used.