Texture Filtering

Here we'll take a look at some of the texture filtering options available on the GeForce 6800 Ultra.

With the GeForce FX series NVIDIA offered an optimised Trilinear / Bilinear mix as the default Trilinear filtering image quality in some driver, but with no option to get full Trilinear. By default GeForce 6800 Ultra has these optimisations enabled, though by selecting the advanced settings in the driver image quality settings panel the optimisations can be disabled with the "Trilinear Optimisations" setting.

Note: For the purposes of benchmarking we will enable full Trilinear filtering on the 6800 Ultra as this is a high end board and quality compromises shouldn't be forced at this price point. However, the optimisations are still enabled for the GeForce FX series with no option to remove them so there will be a filtering disparity in the benchmarks shown.

GeForce FX Trilinear GeForce 6 Trilinear
Base Trilinear
GeForce FX 8x Trilinear Anisotropic Filtering GeForce 6 16x Trilinear Anisotropic Filtering
Max Anisotropy

The above images compares the filtering methods of both GeForce FX on the 52.16 drivers (left) and GeForce 6800 Ultra on the 60.72 drivers (right). We can see that the base Trilinear pattern of GeForce 6800 Ultra has been altered in comparison to GeForce FX and now has the LOD pushed out further at the 45° angles. In the max Anisotropy case 6800 has a new 16X mode, as opposed to GeForce FX's max of 8X, but we can see NVIDIA have also adopted a filtering pattern similar to the one ATI uses with their range of R300 based boards. This particular Anisotropic Filtering pattern is optimal on horizontal or vertical surfaces, but if you go off angle then the maximum degree of anisotropy is reduced. It is thought that the normal GeForce Anisotropic Filtering mechanism is still available within NV40, however its understood not to be presently available in the drivers - presumably the "High Quality" mode of the "Image Settings" option will enable this.

These show the filtering over the other available Anisotropic Filtering modes.

Note that this level of filtering applies to both application and control panel filtering if Trilinear optimisations are turned off. In these cases the base filtering and anisotropic filtering level requested is applied to all layers.

Trilinear Optimised

The above image shows 16X filtering with Trilinear optimisations enabled. It appears that the same level applies across all "Image Settings" selections.