AMD has recently released Catalyst 12.9 driver which adds support to Ubuntu 12.10 (Quantal Quetzal) and Linux 3.5 kernel series. The driver is based on the fglrx 9.00 release and brings more changes, bug fixes, and improvements. The release notes for AMD Catalyst Driver 12.9 is not available currently, but you can get some information about this latest release here.
We will see here two types of driver installation (automatic & manual), but let's first uninstall the current AMD driver with these commands:
sudo sh /usr/share/ati/fglrx-uninstall.sh
sudo apt-get remove --purge fglrx fglrx_* fglrx-amdcccle* fglrx-dev* xorg-driver-fglrx
To install AMD Catalyst 12.9 under Ubuntu 12.10/12.04/11.10 or Linux Mint 13 or older, run the following commands from the terminal:
sudo apt-get install unzip
cd /tmp && wget -O amd-12.9-9.00-EDG_Direct.zip http://goo.gl/mHnCA
chmod +x amd-driver-installer-9.00-x86.x86_64.run
sudo sh amd-driver-installer-9.00-x86.x86_64.run
When the installation is complete, run this command:
sudo aticonfig --initial -f
Finally, reboot your system to activate the new driver. If you have failed installing the driver via GUI mode, you can install it using Recovery Mode as described here.
Note: PPA has not been updated so far, but the driver will be updated very soon. You can check it from time to time here.
To install the driver provided by xorg-edgers, open the terminal and run the following commands:
sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install fglrx-installer