If you're using the proprietary ATI graphics drivers and you're experiencing really slow maximizing / unmaximization of windows or slow Alt + Tab with desktop effects (Compiz) enabled, here is a PPA which is supposed to fix this for you. The package in the PPA should solve this for both GNOME and KDE users.
Some more detailed symptoms of this bug:
- Window Management: Unminimizing, Maximising, Full-Screening, Resizing windows and Switching windows (Alt+Tab) will noticeably freeze the screen for about 1 second plus. Your mileage might vary.
- Memory (RAM) Management: Secondary problem you might notice is memory leak and/or memory-clearing problem
To fix this (important: I didn't test this as I don't have an ATI graphics card!) in Ubuntu / Kubuntu 10.04 Lucid Lynx, use the following commands in a terminal:
sudo add-apt-repository ppa:info-g-com/xserver-xorg-1.7.6-gc
sudo apt-get update
sudo apt-get dist-upgrade
Then you'll have to restart X so log out and log back in!
There is also a PPA for Ubuntu 9.10 Karmic Koala users, but that's not as easy to install as the above PPA: you'll have to force the xorg-server package in Synaptic to version "1.6.4-2ubuntu4.2+backclear1".
Did you try this? If so, did you notice any improvements? Let us know in the comments!