RV100 / 7000VE very slow?

[Christian Brandt]

Today I installed Ubuntu 6.06 on an IBM 346 server which features a
RV100 / 7000VE / 16MB onboard-gpu running at 1280x1024/24bit/60hz. I
have to work for quite some days directly at this system and also in the
future so I have been horrified about the very low performance of the
gpu: Dragging windows lags around half a second, clearing the screen
takes around one second, even while typing inside a terminal window I am
faster than the gpu.

>From my logs:
X Window System Version 7.0.0
Release Date: 21 December 2005
X Protocol Version 11, Revision 0, Release 7.0
Build Operating System:Linux 2.6.15.7 i686
Current Operating System: Linux sword 2.6.15-27-386 #1 PREEMPT Fri Dec 8
17:51:5
6 UTC 2006 i686

The xorg.conf section for the "ati"-module doesn't have any additional
options either. Nothing out of the ordinary otherwise, I haven't been
able to bring the full log outside the server-room. Also the man page
for radeon didn't give me any insight.

After two hours of googling I found only two hints about similiar
problems, one from a 2003 Usenet-Post and one from a recent
opensuse-buglist, both without solution and unresolved until today.

Something else, even though my monitor section only allowed vsync
48-60hz the screen was running at 75hz until I copied a 60hz Modeline
from the log-file-scans into it. Well, not nice but works.

What should I do?

Update X.org myself?

Try VESA?

Any secret speedup-options?

Any better places to ask for help?

Thanks for your help,
Christian Brandt