NVIDIA GeForce 2 GTS Direct3D FSAA Update (Detonator 5.22 Drivers)by Anand Lal Shimpi on May 19, 2000 1:53 AM EST
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It wasn't long ago that there was still speculation as to whether the GeForce 2 GTS or the Voodoo5 5500 would come out on top as the video card of choice for gamers. After the performance benchmarks came in and the GeForce 2 GTS was crowned the performance champion the only advantage the Voodoo5 5500 held over the GeForce 2, other than its price, was the fact that the Voodoo5 5500's drivers featured support for hardware FSAA in OpenGL and in Direct3D. At the time, NVIDIA's 5.16 drivers did not feature support for FSAA in Direct3D, only in OpenGL, but unfortunately most games that you would want to use FSAA in happen to use the D3D API.
NVIDIA just recently sent us their latest beta 5.22 drivers (they are still beta and thus we cannot release them) that enable FSAA support in Direct3D, so how does the GeForce 2 GTS stack up now that it has some (albeit limited) support for FSAA under D3D? Let's first look at the various FSAA modes that are supported by the GeForce 2 and what they do:
(taken from our GeForce 2 GTS Review)
NVIDIA’s FSAA works by using a method called Supersampling. The way supersampling works is that the scene is actually rendered at a higher resolution and then scaled down to the desired resolution before being displayed. As you already know, the higher the resolution you run at, the fewer aliasing effects are present since you have more pixels on the screen to naturally remove those effects.
Under OpenGL applications, NVIDIA’s FSAA can work in one of three modes (much like how 3dfx’s FSAA can be run in either 2-sample or 4-sample mode). The three FSAA settings are as follows:
· 1.5 screen resolution (lowest quality)
· 2x screen resolution, with LOD’s (MIPMaps) at the native game resolution
· 2x screen resolution with MIPMaps at the 2x resolution. (highest quality)
So if you’re running a game at 640 x 480, the first FSAA option will render the scene at 960 x 720 (640 * 1.5 x 480 * 1.5) and then scale it back down to 640 x 480 for displaying.
According to NVIDIA, the only FSAA mode supported in the 5.16 drivers is the highest quality 2x2 setting which is what our GeForce 2 GTS benchmarks were run with originally under OpenGL. The 5.17 and later drivers support the other two FSAA modes unfortunately we are still unclear as to how they are enabled at this point.
The FSAA situation in Direct3D is a bit more flexible. Here are the options NVIDIA’s FSAA offers in D3D:
· 1x supersampling with MIPMaps at the backbuffer (2X higher) resolution.
· 2x supersampling with MIPMaps at the native game resolution
· 2x supersampling with MIPMaps at the backbuffer (higher) resolution.
· 2x supersampling with MIPMaps at the backbuffer (higher) resolution & special filtering algorithm
· 3x supersampling with MIPMaps at the native game resolution
· 3x supersampling with MIPMaps at the backbuffer (higher) resolution
· 4x supersampling with MIPMaps at the native game resolution
· 4x supersampling with MIPMaps at the backbuffer (higher) resolution
The above list features two more FSAA settings than we listed in our original GeForce 2 review. NVIDIA mentioned that the 5.17+ drivers would feature support for a 1x2 mode and a 2x2 mode with a special filtering algorithm that would make it a higher quality setting than the other two 2x supersampling settings. All of these 8 settings were enabled in the 5.22 drivers and they are the settings we used in our tests.