I work on a optiplex 755 with a intel Q35 graphics card. After installing Ubuntu 10.10 (was running XP before that) I could not enable any desktop effects.
I have enabled the package sources and checked for proprietary drivers - none were found.
I can live without desktop effects, but it seems, that any window movement is eating away cpu power.
Normaly I would look at the xorg.conf, but since 10.04 (?) the file is obsolete.