Try going into your ATI Driver Settings through the Catalyst control center and looking through the various settings, chances are the settings are set to Performance and not Quality. (Third-Party software like ATI Tray Tools can also adjust this).
Another possibility is that you're experiencing a Crossfire related issue, you could try disabling crossfire and checking if that fixes it. You could also try using Driver Sweeper and wiping out your old ATI / AMD Drivers and then re-download and install them.
PS: Make sure you use Driver Sweeper in Safe Mode (for obvious reasons).