On Catalyst 8.9 and later ATI drivers now support RandR rotation. After configuring your ati card as usual enter the following string. aticonfig --set-pcs-str="DDX,EnableRandr12,TRUE"
Then restart X11. Your xrandr should work.
Open Source Drivers
ATI Radeon cards 8500,9000,9200 and 9250 working with open source drivers provide OpenGL 3D graphics acceleration.
Proprietary drivers can be used instead, if so desired, although it is not necessary to use these for the cards listed above.
- No support for the built in tuner in "All-in-Wonder" cards.
- Provides some OpenGL 2.0 commands
BUT NOT the OpenGL 2.0 version of the shading language.
The ATI driver uses a version of the shading language called the ARB extension. The ARB extension was used before OpenGL 2.0 was finished.