Comment 8 for bug 339228

CPU jumps up past 50% on the System Monitor graph with both g-s-d and gnome-display-properties (top claims +60% CPU usage for Xorg). I used glxgears below. I'm not sure how I would test with xrandr. xrandr --auto just takes a second and there's no spike on the cpu history. By running xrandr repeatedly maybe there's a slight increase in activity, but nothing over 50% CPU.

glxgears before and after g-s-d

method@discourse:~$ glxgears
get fences failed: -1
param: 6, val: 0
302 frames in 5.0 seconds = 60.187 FPS
301 frames in 5.0 seconds = 60.119 FPS
301 frames in 5.0 seconds = 59.954 FPS
^C
method@discourse:~$ gnome-settings-daemon --debug --no-daemon &
[1] 9295
<snip>
method@discourse:~$ glxgears
get fences failed: -1
param: 6, val: 0
20 frames in 5.3 seconds = 3.771 FPS
17 frames in 5.3 seconds = 3.196 FPS
20 frames in 5.2 seconds = 3.877 FPS

glxgears after gnome-display-properties

method@discourse:~$ bg 1
[1]+ gnome-display-properties &
method@discourse:~$ glxgears
get fences failed: -1
param: 6, val: 0
26 frames in 5.2 seconds = 5.017 FPS
34 frames in 5.4 seconds = 6.310 FPS
31 frames in 5.2 seconds = 5.933 FPS