I just installed the latest 12.8 Catalyst drivers.
I went from 80 fps average in Dirt 3 (Ultra preset, Aspen in game bench, 1080p display with i7370 CPU) to 112 fps.
So all along, I wonder if the drivers I had were the cause of the low scores ( compared to numerous posted examples online, most of which made my fps look like a bad dream.) I wonder if the fps were higher with an earlier version of the drivers.
Release notes claim 10% increase in Dirt 3. From 80 to 112 is much better than that.
Just thought I would note this, in case anyone else had same issue.