If you previously used the proprietary "fglrx" driver it is highly recommended to totally get rid of the fglrx package:
$ sudo apt-get remove --purge xorg-driver-fglrxand reboot the computer.
The libGL.so in /usr/lib might also still be the version installed by xorg-driver-fglrx. You can check that very easily, just run:
$ glxinfo |grep vendorIf you see: client glx vendor string: ATI, then the libGL.so is still from ATI. Make sure libgl1-mesa-glx and libgl1-mesa-dri are properly installed:
$ sudo apt-get install --reinstall libgl1-mesa-glx libgl1-mesa-driOf course, make sure your xorg.conf does not contain any "fglrx" entry.
sudo vim /etc/X11/xorg.conf
sudo nano /etc/X11/xorg.conf
Configuring your graphics card "Device" section
You first of all have to find the device section already related to your graphics card. It can have any name, or might even not exist if you are just installing your xserver. You can usually find it right after your mouse entry.
It should look like this:
Identifier "Radeon 9200"
The "Monitor" section
This is what your monitor section should look like:
Identifier "Generic Monitor"
The "Screen" section
It will basically look like that:
Identifier "Default Screen"
Device "Radeon 9200"
Monitor "Generic Monitor"
For cards low on video RAM, you might need to add a "Virtual" line to the "Display" subsection of the "Screen" section in xorg.conf, since the default values (see /var/log/Xorg.0.log) are a bit "greedy" on memory.
Virtual 1280 800
Set the x and y values according to the wanted maximum size of your virtual desktop.
Add the following sections at the end of the file if they don't exist elsewhere:
Option "Composite" "Enable"
EndSectionThen check the "ServerLayout" section:
Option "AIGLX" "true"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
The AIGLX option is to enable AIGLX for fancy 3D desktop effects. Identifier should not be changed. Screen is the name you gave to your screen in the screen section. InputDevice are for the devices you want to use (with a section device in this file) and which are not your graphics card or monitor.
Restart and get a new accelerated desktop!