NVIDIA GeForce4 - NV17 and NV25 Come to Life

Anisotropic Filtering Performance

With the release of ATI's 7.66 beta drivers they have integrated an anisotropic filtering control panel into the Radeon's driver set thus making it much more user friendly to enable this higher quality filtering. The new slider in the drivers will actually select the maximum degree of texture anisotropy that will be used, the Radeon hardware will calculate what levels of anisotropy should be used depending on the situation thus giving the Radeon 8500 a much smaller performance hit when anisotropic filtering is enabled.

Unreal Performance Test 2002 Anisotropic Filtering 16-tap - 1024x768x32 NVIDIA GeForce4 Ti 4600 NVIDIA GeForce4 Ti 4400 ATI Radeon 8500 NVIDIA GeForce3 Ti 500 NVIDIA GeForce3 NVIDIA GeForce3 Ti 200 NVIDIA GeForce2 Ti 200 NVIDIA GeForce4 MX 460 NVIDIA GeForce4 MX 440 61.4 56.3 51.4 51.3 47.5 42 32.4 18.7 15.1 | 0 | 12 | 25 | 37 | 49 | 61 | 74

Here we see that although the GeForce4 drops significantly in performance, the Radeon 8500 realizes a very small performance penalty and all of a sudden is within 20% of the fastest GeForce4; again this is because of the Radeon's more efficient anisotropic filtering algorithm.

Unreal Performance Test 2002 Anisotropic Filtering 16-tap and 2X FSAA - 1024x768x32 NVIDIA GeForce4 Ti 4600 NVIDIA GeForce4 Ti 4400 NVIDIA GeForce3 Ti 500 ATI Radeon 8500 NVIDIA GeForce3 NVIDIA GeForce3 Ti 200 NVIDIA GeForce2 Ti 200 57.2 51.9 47.7 26.8 26.5 24.7 22.4 | 0 | 11 | 23 | 34 | 46 | 57 | 69

One thing we proved in our last AA investigation is that in order for the visual quality of NVIDIA's multisampling AA to equal that of ATI's supersampled AA on both an anti-aliasing and a texture quality level NVIDIA cards had to be run with 16-tap anisotropic filtering enabled in conjunction with their AA mode. Enabling anisotropic filtering on the Radeon 8500 won't hurt performance all too much but turning it on with the Radeon's supersampling AA at the same time reduces performance significantly.

The GeForce4 takes much less of a hit when simply enabling 2X AA because of its more efficient multisampling algorithm.

Unreal Performance Test 2002 Anisotropic Filtering 16-tap and 4X FSAA - 1024x768x32 NVIDIA GeForce4 Ti 4600 NVIDIA GeForce4 Ti 4400 NVIDIA GeForce3 Ti 500 NVIDIA GeForce3 ATI Radeon 8500 NVIDIA GeForce3 Ti 200 NVIDIA GeForce2 Ti 200 43.6 38.2 28.7 19.8 18.9 18.7 11.8 | 0 | 9 | 17 | 26 | 35 | 44 | 52

The same story can be told with 16-tap anisotropic filtering enabled and 4X AA. This time there is much more of a performance difference between the GeForce4 Ti 4600 and the GeForce3 Ti 500 because of the increase in memory bandwidth dependency.