Comment 4 for bug 449196

Compare your process listing (`ps aux`) from this 25% case with the high cpu case (if you can still reproduce the issue). Examine each process listed in the latter case but not the former.

*Usually* high X CPU is caused by some other X client process making too many requests of the X server. These cases aren't bugs in the X server but rather in the client application (perhaps it's stuck in some loop that makes excessive X calls).