Now, the last thing we have to do is check the performance drop occurring in the three modes by GeForce FX when we enable anisotropic filtering. As usual, we will compare the results with those shown by ATI RADEON 9700 PRO.
Our first benchmark is Unreal Tournament 2003. The game uses Direct3D. Game settings looked as follows: Texture Detail: Highest, World Detail: Highest, Character Detail: Highest, Physics Detail: Normal, Character Shadows: ON, Dynamic Lighting: ON, Detail Textures: ON, Projectors: ON, Decals: ON, Coronas: ON, Decal Stay: Normal, Foliage: ON, Tri-linear Filtering: ON. We ran the Antalus flyby-scene.
We used “Speed” and “Quality” settings for ATI RADEON 9700 PRO in Direct3D as well as in OpenGL. The settings are those as shown in the above driver screenshots with one exception – we were moving the anisotropy level slide-bar to different positions.
We made almost no mistake by promising a “nearly cost-free” 2x anisotropic filtering in the “Aggressive” mode by GeForce FX. But this “nearly” amounted to 12% in the highest resolution. In the “Application” mode with true tri-linear filtering, NVIDIA GeForce FX has to perform anisotropic filtering in the way GeForce4 does, so they have similar performance drops. The performance reduction in the “Balanced” mode is in-between the two other modes by GeForce FX.
It is interesting, but the turned-on 2x anisotropic filtering in the “Speed” mode by ATI RADEON 9700 PRO leads to an increase in speed: the absence of tri-linear filtering allows more efficient use of texturing caches.
In the “Quality” mode, the adaptive anisotropic filtering algorithm implemented in RADEON 9700 PRO allows the solution to sacrifice less performance compared to the highest-quality “Application” mode on GeForce FX 5800 Ultra, which uses the same anisotropic filtering method as NVIDIA GeForce3 / GeForce4 chips.
The higher levels of anisotropy result in a bigger performance drop for all cards in all work modes. But the general picture remains the same: ATI RADEON 9700 PRO in the “Speed” mode is fastest, followed by GeForce FX in “Aggressive” and “Balanced” modes. ATI’s “Quality” comes next; GeForce4 and GeForce FX in the slowest, but best-quality “Application” mode are in the rear.
To check the cards’ behavior in OpenGL, we used Quake3 Arena v.1.30. The settings for all the cards were as follows: 32-bit texture color and frame-buffer depths, maximum amount of textures and objects, enabled tri-linear filtering, disabled texture compression.
Quake3 Arena loads the graphics card less than Unreal Tournament 2003, so we have a lower performance drop caused by anisotropic filtering here. But the results ratio remains unchanged, with that only difference that the performance drop of GeForce FX in the “Application” mode is just a little higher than of ATI RADEON 9700 PRO in the “Quality” mode.Winding up this section of the review, we should acknowledge the quality and speed of anisotropic filtering as performed by GeForce FX. The evolutionary development of NVIDIA’s anisotropic filtering implementation is surprisingly successful. If you are not satisfied with the speed in the best-quality “Application” mode, you can switch to “Balanced” and increase the GPU speed without losing much of the image quality. And if this speed is still not enough for you, switch to “Aggressive”, but try to disregard possible texture “ripples” and some compression artifacts then.