one culprit was the RT kernel installed by Ubuntu-Studio
Linux uhuru 2.6.24-23-rt #1 SMP PREEMPT RT Wed Apr 1 23:40:34 UTC 2009
I removed this and installed Linux uhuru 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 and performance is immediately much improved, Xorg shows drm now installs and radeon and drm are now both in the lsmod listing.
the upgrade apparently misses replacing the RT kernel, which makes sense (in retrospect) since Cannonical does not support the RT kernel images.
one culprit was the RT kernel installed by Ubuntu-Studio
Linux uhuru 2.6.24-23-rt #1 SMP PREEMPT RT Wed Apr 1 23:40:34 UTC 2009
I removed this and installed Linux uhuru 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 and performance is immediately much improved, Xorg shows drm now installs and radeon and drm are now both in the lsmod listing.
the upgrade apparently misses replacing the RT kernel, which makes sense (in retrospect) since Cannonical does not support the RT kernel images.