Created attachment 40120 [details] [review] Xserver log When I enable desktop compositing with KMS things get so slow that it's basically unusable. The card I use is a Radeon X800 R420. Of course I'm aware that this is not the latest model, but IMHO it should be perfectly usable for simple desktop compositing. This is with KDE 4.5.2 btw.
Created attachment 40121 [details] [review] DMESG output
Are you using GL or render for composite? Does removing the MigrationHeuristic line from your config help? Does upgrading to xf86-video-ati 6.13.2 or newer help?
(In reply to comment #2) > Are you using GL or render for composite? GL > Does removing the MigrationHeuristic line from your config help? Jep, this helps quite a bit. Things like scrolling webpages, dragging windows or expose effect are still stuttering, but this is also with UMS. > Does upgrading to xf86-video-ati 6.13.2 or newer help? No. I tried 6.13.2 from the Ubuntu X-Updates repository. (I only tried this in addition to removing MigrationHeuristic.)
(In reply to comment #3) > (In reply to comment #2) > > Are you using GL or render for composite? > GL In that case, this is an issue with the 3D driver. kde is apparently hitting some slow path. What version of mesa are you using? You might try mesa 7.9 or the r300 gallium driver if you are using the r300 classic driver.
Ok, I upgraded mesa to Ubuntu xorg-edgers packages. glxinfo now says: OpenGL vendor string: X.Org R300 Project OpenGL renderer string: Gallium 0.4 on R420 OpenGL version string: 2.1 Mesa 7.10-devel No noticeable speed improvement however. Anyway, this is now more a general speed issue. I'd *expect* things to be faster with this card, but may it's just too slow for this kind of usage. Removing MigrationHeuristic=greedy brought KMS on par with UMS for me and that was what the original report was about. So I guess it can be closed. Perhaps it would be good to document this in the radeon manpage, as greedy is suggested in most tutorials on the web about getting radeon faster.
I'm also experiencing this problem. The notebook has a X1400 card installed and I'm also using KMS + Gallium (git). I've opened a bug report at KDE: https://bugs.kde.org/show_bug.cgi?id=253903 but so far there's no solution to the problem.
The classic r300 driver has been abandoned long ago. It was replaced by the Gallium driver r300g. If you have issues with r300g please file a new bug report with component Drivers/Gallium/r300 Thanks.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.