If your desktop is set at your screen's native resolution.

If you can't get a speedup by playing at lower resolutions in a window, and.

If you're playing at your screen's native resolution, and.

So, if getting every single last drop of framerate is your priority here, only play in fullscreen mode:

A notable exception is certainly Ubuntu (which can draw notifyOSD notifications on top of games) I don't know how Macs work here. If your desktop resolution is not your game resolution, by all means do play in windowed mode.įullscreen mode at non-native resolution means that instead of shifting graphics output to a rectangle on the screen (something relatively fast), your computer instead has to scale the picture from the game resolution to your native resolution with bicubic filtering or better (expensive!).Įven if it is your monitor itself that does the heavy lifting, or if you disabled hardware scaling at higher resolutions (in which case you still have to translate pixel coordinates), you will get terrible performance and occasionally crashes whenever you Alt-Tab from and to the game.įinally, not all operative systems allow you to skip the screen compositing system altogether. Honestly, however, on my dated hardware I take a much greater performance hit by running games at desktop resolution than I do by playing at a lower resolution through the window manager. If your game resolution is your desktop resolution, then fullscreen is likely to be slightly faster than windowed mode in all scenarios, for the reasons enumerated by Philipp.

Fallout 3 fake fullscreen not working