Anisotropic Filtering, FSAA Performance Impact
We were extremely excited about anisotropic filtering for “free” with the DeltaChrome S8 and could not miss the opportunity to experience that thing once again. Well, we were a bit disappointed, but our expectation about anisotropic filtering without performance impact did not materialize.
If there is a technology to allow “free” anisotropic filtering on the DeltaChrome, then it does not work at this time with certain games and/or is driver-dependant. At least, UT2003 shows pretty different performance with anisotropic filtering turned on compared what we had three months ago. Another explanation to the phenomenon is that there probably was something with S3 Graphics’ drivers, which degraded performance in normal mode to the point of speed with a certain level of anisotropic filtering enabled. For instance, DeltaChrome could use 2 texture samples to emulate 8x, 16x anisotropic filtering. This resulted in pretty sharp, but a bit noisy textures. Provided that the issues are corrected now, performance should degrade according to the level of anisotropic filtering.
Please have a look on diagrams that represent dependence of UT2003 performance on the level of anisotropic filtering:
Speed of S3 DeltaChrome S8 Nitro waterfalls once anisotropic filtering is enable just like that of other graphics chips.
The situation with Inferno demo is practically the same as with Antalus level. S3 DeltaChrome S8 Nitro does not provide “free” anisotropic filtering, unfortunately.