Anisotrope Filtering
Matrox Parhelia only offers 2x anisotropic.
ATi plays its trump card in anisotropic filtering. Unlike NVIDIA, ATi doesn't filter all textures using the specified filter level; instead, it decides how much to filter the texture depending on the angle of the texture to the viewer. NVIDIA has accused ATi of increasing performance to the detriment of quality. In reality, though, it's hard to spot any differences. Intriguingly, ATi has recently added "adaptive" to the list of adjectives describing its filter technology. Because the Matrox Parhelia is unable to filter 8x anisotropic, it was tested with a lower quality level (2x). It was still the laggard of the group.
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