Lucid Muddle

Sun, 02 May 2010 01:15:00 +0100

Today I did the Kubuntu Karmic to Lucid upgrade on my Thinkpad T60 with 2GHz Core Duo CPU, 3GB RAM and ATI Radeon Mobility X1400 GPU.

The upgrade itself went ahead flawlessly but I started to see problems after the desktop started. Things seemed generally sluggish, especially moving windows around and scrolling, and it seemed to get worse over time. Flash video was very teary and unwatchable fullscreen. When I tried to play a 3D game it caused a strange horizontal black line interference that didn't go away until I rebooted. Also, seemingly unrelated, the wireless network would lose connection after a while and refuse to reconnect until I switched the wireless kill switch off and on again.

The solution to all these problems seems to have been to switch off Kernel Mode-Setting. I did this by editing the file /etc/default/grub and changing the line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.modeset=0"

Then running update-grub and rebooting. This has resulted in a much more stable desktop, but at the cost of making the boot splash screen look very ugly indeed. The wireless connection now works perfectly.

Now it's working properly the KDE desktop with compositing seems much more responsive than on Karmic. I might even leave effects turned on this time. Video is fine and 3D games work reasonably well, I've had trouble with 3D stuff before. I'm still seeing a fair bit of corruption on icons and window decorations, something I've seen ever since switching to the open source ATI driver.

So generally Lucid is looking good and I'm liking the new stuff in KDE 4.4. Perhaps it's still a bit early to be enabling the kernel stuff for the radeon driver though.

barnoid.org.uk - The website of Barney Livingston : Tag ati, everything about ati

Lucid Muddle