bi/trilinear filtering has a massive performance advantage over anisotropic, if ATI is dropping back to bi/trilinear, then there will be a performance increase. I'm still very curious about all this talk about angle independent anisotropic filtering, as the the view angle is what determines the line of anisotropy and therefore the sampling region, bi/tri linear is angle independent as the sampling region is always uniform.

everywhere you look you see that one screen shot of the round rings and everyone uses that as proof of how good the ATI filtering implementation is, unfortunately the major problems in regard to texture filtering, which a lot of the posters above me don't get, is that the problem occur during motion.

Ever notice how a texture all of a sudden "pops" from low res to a sharper version? that's bi-linear filtering, trilinear smooths this out by interpolating between the mip levels, so the transition is smoother and anisotropic is a special case of trilinear, created to reduce the aliasing of oblique textured surfaces.

perhaps ATI figured that no one would notice their "feature" and so enabled it to gain extra performance but just like everyone else in this thread I want some proof:

* compare the 10.3s to the 9.12s and see if this "feature" is present
* compare filtering across games and APIs, might be a DX10 only "feature"

Someone should also post a performance comparision between bilinear / trilinear / 8x anisotropic and 16x anisotropic in this thread just to quiet down the guys claiming its not a big deal.

I know for a fact that the graphics programmer has absolutely NO control over how filtering is performed, all he can do is enable/disable it. The actual implementation of the algorithm is company specific and in the drivers.