Comment 1 for bug 149962

Thanks for reporting bugs. It is excluded we disable compiz each time the desktop goes to fullscreen mode, because it's slow, may bring new issues and would only be a horrible workaround.
On the other hand, please give more information on your problem and we will try to solve this bug without disabling compiz. Compiz should not slow your system when playing.
Which graphics card model do you have? What means "slow"? Are you only experiencing this with compiz enabled?