SmoothVision

Like NVIDIA's Quincunx, ATi's "SmoothVision" FSAA technology is based on Multisampling. This FSAA method allows for much higher framerates than the SuperSampling method which was used in the GeForce 2 series and the older RADEON. For a more detailed explanation of these FSAA techniques take a look at this article: (Tom´s Hardware Guide).

ATi is taking anti aliasing one step further, refining a bit more. Since MultiSampling FSAA always produces slightly blurred textures due to the way this technique works, it is inherently inferior to the SuperSampling method in this respect. ATi is attempting to ameliorate this problem by using SmoothVision, letting the user choose between maximum quality or maximum performance. While the second option is obviously optimized for speed, the first uses larger textures and therefore requires more memory and more bandwidth. Additionally, the textures are filtered, producing a much crisper result. Next to the usual 2x and 4x FSAA modes, the new drivers also offer settings for 3x and 6x. The "Quality" and "Performance" levels allow different maximum resolutions. Here's a chart:

The following screenshots (taken in Quake 3) show the differences:

(Download as uncompressed BMP - 800kb)

A closer look at these images reveals the differences between the FSAA implementations and settings. At 2xFSAA, the Ti500 does a better job of smoothing the jagged edges but offers lower texture quality - even when compared to ATi's performance setting. At the 4x setting, differences are very hard to make out - the results on both cards are nearly identical. Once again the Ti500's image is less crisp than the RADEON's. This effect becomes even more pronounced when NVIDIA's Quincunx mode is used.

ATI's SmoothVision is aimed squarely at quality. Apparently (anisotropic) texture filtering is enabled by default - unlike NVIDIA's solution. The ATI driver offers two settings for Anisotropic filtering: High and Highest. More on that later in the article. The GeForce 3 supports 16tap, 32tap, and even 64tap. Although these settings have theoretically been supported since the 12.xx NVIDIA family of drivers, the drivers themselves lack a way to change them. The options can only be set by manually editing the registry or with the help of freeware tools like NVMax.

Let me repeat: The "GeForce Ti500 - Xx FSAA - 64tap" mode is not available in the standard NVIDIA drivers in this form. The reason behind this is unclear, as this level of quality is unavailable to the RADEON 8500 at this point.

Using the standard FSAA settings the GeForce 3 is roughly twice as fast as the RADEON 8500 - but with visibly lower image quality. Yet even with forced 64tap anisotropic filtering the Ti500 can maintain its lead over the R8500 - while offering outstanding image quality. In light of these results it is unclear why NVIDIA isn't officially offering this setting.

We can conclude that at this point ATi's SmoothVision is slower than NVIDIA's FSAA method. The following benchmarks prove that this has nothing to do with filtering.

Copyright: 20.11.2001 -   RIVA Station 2001 - Lars Weinand
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