I did the tests above again, but now included the results for single-monitor setups, and without any other apps running. extended screen, 17" monitor: Total time: 15.06 extended screen, 24" monitor: Total time: 47.58 $ xrandr --output DVI-0 --off single screen, 17" monitor: Total time: 14.97 $ xrandr --output DVI-0 --auto --rotate left dual screen, display clone: Total time: 15.77 $ xrandr --output VGA-0 --off single screen, 24" monitor: Total time: 15.12