Furyhunter

V-Sync is, as you described, a wait for vertical refresh sync. Its purpose is to stop the tear lines though, not provide "smooth scrolling". It has a significant performance impact on almost any system due to the way it works, but enabling Triple Buffering helps (and requires more VRAM). Personally I've never liked the way MMF/2 implements it. The end-user should have the option to enable and disable it, and I'm pretty sure Clickteam still hasn't made a system variable that can be modified during runtime to allow this. Honestly, just keep it turned off for safety and if someone wants it they can use their driver control panel to force it. (in DirectX) Also note that on most digital displays (like LCD) vsync has almost no visual benefit.