Comment 142 for bug 803943

All, FYI, there are many different reasons why compiz uses lots of CPU in some cases. Often Unity is the cause, and often it's an indicator (like multiload -> bug 784055). There is also still some overhead in inefficient rendering that could be improved.

I think this bug has just become a general discussion forum, making it highly unlikely that a single cause will be cited and agreed upon.

Instead, if you can find that something in particular causes compiz to use high CPU, or can find something that prevents it, then please log a separate bug about each particular issue. That way each problem is likely not be triaged and fixed in a more manageable way.