Comment 23 for bug 985661

Same issue here. My machine is doing nothing but running a few gnome-terminal sessions, and the load average is:
    1.12, 1.00, 1.05

The top few items in top are almost always:

 1094 root 20 0 327m 136m 15m R 11 6.8 45:20.30 Xorg
 1754 jamesj 20 0 1329m 85m 37m R 5 4.3 51:14.45 compiz
 1879 jamesj 20 0 576m 23m 11m S 3 1.2 34:37.32 unity-panel-ser