Originally Posted by TobiSGD
I would recommend exactly the opposite. It is well known that tearing in XFCE can be eliminated (or at least seriously reduced) by adding a compositor like Compton. That is why I asked which DE/WM is in use.
Yeah, you can reduce the tearing on dragging desktop items and whatnot because the output is translated into opengl (but the tearing is minimal anyway, at least with nvidia or radeon/r600+glamor with latest git mesa+kernels).
But if you play back some video its easier to set it to output on opengl or vdpau. Best is vdpau (OOTB vsync that works well) but that doesnt work on intel or fglrx (it does work on nvidia, nouveau and radeon's newer than hd2000/3000 cards).
Opengl does the job just fine, but make sure vblank is on by default for your cards drivers (the OSS drivers tend to have it on by default).
Using compton to "straighten stuff up" when playing video leads to inconsistent/low frame rates, stuttering (same goes for fglrx' tear free option btw). Yes, it does have an "unrediect fullscreen app" option, but that didnt always worked for me.
DO NOT use the built in xfce compositor - while it does have a vsync option, it doesnt work well with video playback or games (=tearing+high cpu usage) - because its a software based compositor.
Games are a totally different category, the different 3d engines leading to different results regarding vsync. Some work well, some dont (even if they have a vsync on switch). Starting any opengl application preceded by vblank_mode=1 enables vblank usage by default (0 disables), but even then the engine might override it.