Originally posted by jbirney
ATIs method is the same on the 8500 as it is on the R9700 just with Tri-linear and an angle tweak. Its been shown on a GF4 vrs 8500 comparison that once you hack down the GF4 to also only do Bi/AF (so you level the playing field so to speak) that the 8500's AF had a lower performance hit.
I've already explained the primary reason that the GeForce4 has so much of a performance hit. If the first texture has anisotropic enabled, the second texture does not go through. That is, disabling anisotropic for the first and third texture stages results in a huge performance increase. While using bilinear filtering does allow for some improvement in performance, it doesn't come close to the improvement from doing what I described above.
And I have yet to see any ATI representative give a satisfactory answer. Any links?