If you're using a recent Radeon card (HD 7000 series GPUs) then you'll also want it regardless. Unity can't run, otherwise.
If you currently run a previous version, then you'll want to uninstall the previous Catalyst driver first.
~$ sudo sh /usr/share/ati/fglrx-uninstall.sh
You'll need to reboot. Then, it's time to get the latest drivers.
~$ wget -c http://www2.ati.com/drivers/linux/amd-driver-installer-12-6-x86.x86_64.run~$ sudo sh amd-driver-installer-12-6-x86.x86_64.run
Reboot one more time after completing the installation and you should be back to hardware accelerated desktop.