How To: Fix your screen configuration when using ATI Catalyst™ Proprietary Linux Display Driver

The team play of Ubuntu and ATI graphic cards is something I wouldn't bet my shirt on. At some point it's still a mystery for me to configure it correctly, the effects of changes in xorg.conf, driver updates, use of aticonfig or Ubuntu's display configuration tool give a surprise every time and if suddenly things are working correctly I call it a miracle. Unfortunatly after having benefited from a miracle for quite some months, things stopped working again for no apparent reason.

At some point the driver seems to not listen to xorg.conf any way. It writes its own configuration into /etc/ati/amdpcsdb and this file gets messed up after some time. So at any start of trying a new configuration its seems wise to replace it with the /etc/ati/amdpcsdb.default file.

But still the xorg.conf file seems to have some influence on graphic settings. So for a fresh start also completely remove /etc/X11/xorg.conf and do a aticonfig --initial --force which will give you a completely new one based on the configuration this ATI tool detected.

After doing both of this still strange things were happening in my Ubuntu installation. Logging into GDM with my user profile gave unexpected and unwanted results in display configuration, logging in with another user profile worked perfectly well. The reason for that: user-dependent GNOME Display settings in the home directory in ~/.config/monitors.xml. Delete this file to prevent Display chaos.

So we can finally start adapting the new configuration now. This should be done in the CCC (Catalyst Control Centre). I hope things go well from here for you too. Good luck.