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SMOOTHVISION and ATI Displays The real meat of the Radeon 9800 Pro is found in the new ATI Displays control panel, which is used to control SMOOTHVISION, ATI's marketing term for full-scene anti-aliasing (both super-sample and multi-sample) and anisotropic filtering. Basically, full-scene anti-aliasing eliminates the stair-stepping effect and shimmering textures. The multi-sampling (MSAA) method is much more efficient than super-sampling (SSAA) and offers similar, if not equal, improvements to image quality. Anisotropic filtering increases the texture quality of polygons that lie at an oblique angle relative to the plane of the screen. When the two are combined, the resulting improvement to image quality in games is amazing.Unfortunately, these enhancements come at the cost of reduced performance, but in most cases, it is not as severe as you may think. A relatively slow processor — any single processor G4 or G5 system — will not be able to send data fast enough to saturate the Radeon 9800 Pro. The unused memory bandwith and fill rate can be used for FSAA and AF with virtually no performance penalty. Even when powered by a dual 2 GHz Power Mac G5, the framerate may take a steep dive from, say, 200 to 100 FPS with FSAA and AF enabled, but the game will still be perfectly playable. Anti-aliasing and anisotropic filtering are controlled by the OpenGL Overrides tab in ATI Displays 4.1. The control panel allows users to create a unique profile for each game and customize the FSAA, AF, and vertical sync settings. When the game is launched, the respective profile is automatically loaded, whose settings take precedence over the in-game settings. This feature eliminates the annoyance of having to manually fiddle with the settings for every game and is exclusive to the Mac. As you can tell from the screenshot above, the interface is self-explanatory. To edit an application's settings, you select the profile from the pull down menu. The preset menu has three pre-programmed profiles and you can create your own, or have unique profiles for every application. The performance slider may be the only ambiguous widget, but it seems to affect texture quality by adjusting the level of filtering applied to the scene.
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