Ubuntu Tutorials

Ubuntu 9.04 unfortunately had some significant regressions in regards to video on Intel based hardware. I have an onboard Intel GM965/GL960 and I noticed the video was a lot more choppy and glitchy after installing Ubuntu 9.04. This issue has been addressed and seems to be fixed in the latest alpha releases of Ubuntu 9.10, but if you don’t want to wait you can try to fix it yourself with the following steps. I just applied these fixes to my machine and I’ve noticed a significant improvement!

xorg.conf backup

To apply these changes you’ll need to manually update your xorg.conf file. It is good practice to make a backup of this file before you alter anything, as a broken configuration will result in a non-working graphical interface. The following two commands will 1) make a backup and 2) open the file for editing:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg-$(date)
sudo vim /etc/X11/xorg.conf

Section “Device”

You’ll want to look for a section in the configuration that starts with Section “Device” and add some options within that block. The primary option you’ll want to add is the AccelMethod. You can see an example below:

Section "Device"
Identifier "Configured Video Device"
Option "AccelMethod" "uxa"
EndSection

You’ll need to re-login for the changes to take effect, but you should notice a difference.

Additional Options

I’ve also added a few other options to my configuration which you might want to try out. Below is the configuration I’m using:

Section "Device"
Identifier "Configured Video Device"
Option "AccelMethod" "uxa"
Option "EXAOptimizeMigration" "true"
Option "MigrationHeuristic" "greedy"
Option "Tiling" "true"
EndSection

Remember, before you apply any of these settings you should make a backup of the file. If one of your changes doesn’t apply properly, or isn’t supported you may end up with no graphical environment at all. You’ll only have the console available to fix / revert your changes. A backup will make “fixing” the problem much simpler.

With the release of Ubuntu 9.04 the keyboard combination to restart the X server was disabled. This, I think, was due to reports of users accidentally hitting the combination and having X restart resulting in lost work. I will admit that I may have hit that combination once or twice in my time, but its pretty rare. In this post I’ll outline how to re-enable that keyboard combination, allowing you to use ctrl-alt-backspace to restart X.

DontZap

To re-enable the ctrl-alt-backspace keyboard combination to restart the X server install the package dontzap:

sudo aptitude install dontzap

All this package basically does is update the xorg.conf file to set Option “DontZap” ” false”.

You can then manually toggle between enabling and disabling the keyboard combination using the commands:

sudo dontzap --disable

sudo dontzap --enable

If you would like to make these changes manually (without installing the package), you can make changes by hand to your xorg.conf file. Simply add the following section within your /etc/X11/xorg.conf:

Section "ServerFlags"
Option "DontZap" "false"
EndSection

You will likely need to re-login for any of these changes to take effect.