How to stop compiz taking so much processor power in 12.04

[user1]

I am running unity 3d and found out my my airblower was running fairly 
steadily and then I saw that compiz took some 37% of cpu power most of 
the time.
The whole system was a bit slow
Now I am using unity 2d and everything is running fast, smooth and fairly 
quiet.
Is it possibly to stop compiz taking so much power in unity 3d?
I checked 'stop showing thumbnails' in gwenview and now even that program 
is using much less cpu power and is more convenient to use.
Wonder if there are some other setup to tweak to reduce general power 
comsumption in unity 3d
This is more or less a general principle questions to improve unity 3d 
and making it more convenient for the users?