Comment 124 for bug 803943

I can confirm that CPU usage drops significally when vsync is disabled. To be specific:
Vsync enabled: When computer is completely idle compiz cpu usage is 1-2 %
                            When dragging the terminal window gently compiz cpu usage is approx. 30-35 %

Vsync disabled: When computer is completely idle compiz cpu usage is 0 %
                             When dragging the terminal window gently compiz cpu usage is approx. 15%
                             The bad thing is that disabling vsync causes other significal problems such as not smooth window moving!