In our High Quality tests we bump the Antialiasing (AA) and Anisotropic Filtering (AF) up causing the card(s) to be put under more load.
This usually helps us remove the CPU limitation. We use 4 x AA and 8 x AF as this is quite a common setup for most people who are venturing into the AA and AF area.
When it came to testing AA and AF we found that there was a slight dip in performance but nothing that you would worry about. This is something ATI will most likely fix before the next official driver release.
