Weird Pauses Ubuntu Jaunty in Compiz / ATI fglrx

I upgraded my laptop to Ubuntu Jaunty the other day. A relatively smooth upgrade, but one thing was really annoying me.

The open source drivers for the machine don’t support compiz effects, which I’ve come to rely on for genuinely useful task switching, inverting the colours of windows, and magnifying. So I used the proprietary ATI fglrx drivers. All worked well apart from a really annoying several-second delay each time a window was maximized or resized.

I couldn’t find anything relevant on the interwebs until today. Apparently this issue is widespread, and is the result of the xserver “back filling” any maximized or resized windows to prevent momentary display corruption within that window. This goes really slowly!

There is now a patch – basically just an xserver which abandons the back filling. The appropriate repositories can be found here: