Anisotropic Filtering Performance Scale
When testing the performance of ATI's different anti-aliasing modes a couple of pages back, we stepped through each successive level of AA while benchmarking FarCry at resolutions of 1280x1024 and 1600x1200. The results on this page were attained using a similar methodology, but we altered the level of anisotropic filtering being applied to the images instead. Anti-aliasing was disabled throughout this batch of tests to isolate the effect anisotropic filtering alone was having on performance.
As expected, as the level of anisotropic filtering being applied to the scene was increased, performance decreased. But unlike the anti-aliasing results, where adaptive AA dragged performance down significantly, ATI's new high-quality anisotropic filtering modes had a negligible impact on performance, at least in FarCry. In fact, the difference in performance between the no-aniso tests, and the tests where 16x high-quality anisotropic filtering was applied was less than 10%. We'd have to do more extensive testing with a multitude of games to make any broad, sweeping statements, but initially, it seems like there is no reason not to enable high-quality anisotropic filtering on the X1000 family of cards. There in a minimal effect on performance, but a noticeable increase in image quality while gaming.