For those experiencing lagging graphics with ATI cards.

[sienile]

I recent Ubuntu update has caused a performance issue with my (and most likely many other's) ATI graphics card. This issue is only present with the proprietary drivers downloaded from ATI's site. To solve the problem, you must revert to the repository drivers until either Ubuntu or ATI Catalyst is updated.

Here's how you do it:

sudo apt-get install fglrx fglrx-amdcccle

sudo aticonfig --initial

Then reboot and you're done.