Comment 113 for bug 1386721

I found a similar bug #1314587 but for unity, perhaps X.org is the culprit here. I still get this occasionally, although I'm using the fglrx driver.

I tried disabling PAT memory in xdiagnose only, rebooted and then got the exact same performance as the original reporter. After reverting the change everything was ok, but as I mentioned before, I still get poor performance from time to time.