I have been having a hard time getting the composite effects running smoothly on KDE4 with my intel Mobile 945GM graphics card. But I have finally managed to get it up and running! This is how:

1. Get the latest intel driver from your repository (I have 2.3.2)
2. Put into xorg.conf at the driver section:

   Section "Device"
   Identifier      "Configured Video Device"
   Driver "intel"
   Option "DRI" "true"
   EndSection

3. Put at the end of your xorg.conf:

   Section "DRI"
   Mode 0666
   EndSection
   
   Section "Extensions"
   Option "Composite" "Enable"
   Option "DAMAGE" "Enable"
   Option "RENDER" "Enable"
   Option "RandR" "on"
   EndSection

4. Under the system settings, enable desktop effects and set in the advanced settings to use XRender! (and take out the update thumbnails and the smooth scaling).
5. Restart X: restart the computer or just do: logout then push “ctrl+alt+backspace”, log in to the console as root, and restart kdm by issuing: “/etc/init.d/kdm restart”.

I have by the way, a Dell D430, so an extremely lightweight, small computer that probably has the worst performance among its peers, and the effects are *fast* I must say that the “coverflow” effect (not enabled by default) isn’t that great, something is wrong with it, but still: scrolling is super-fast, switching windows is super-fast, so you won’t notice any slowdown at all!