Test: Leadtek WinFast GeForce 2 PRO (12/14)

AntiAliasing

Anti aliasing smoothes the jagged contours that are usually present around the edges of 3D objects in 3D games. These "jaggies" are especially pronounced in lower resolutions and can really detract from your gaming experience. The concept behind FSAA is really quite simple:

The image is rendered internally at a higher resolution and is then scaled down to fit the resolution selected. Each pixel of the "shrunken" image is the average of several of the pixels in the high-res version. For 2x2 FSAA, the picture is rendered at twice the original resolution internally. Then (at 2x2 FSAA) a 4x4 matrix is projected over the picture and used to scale down the image to the original resolution by averaging the color values of the 4 adjacent pixels within the matrix.

But usually there are still some more calculations needed. Example: 2D elements like the dashboard in a flight-sim or a racing game. These need to be scaled separately and have to be added before the internal image is scaled back down to size. In some games, the NVIDIA drivers sometimes still have some trouble with this step. Additionally, the image also gets filtered during the scaling-down phase. To make it short: FSAA means lots and lots of work for the chip and especially the memory, since enormous amounts of data need to be transferred for every single frame! That's why FSAA is really only practicable in low resolutions and under 16Bit color so far.

Point of information: contrary to some rumors, the GeForce2's FSAA technique is not a software solution. The whole process takes place almost exclusively on the chip. The T&L engine takes care of the entire scaling operations, for example.

2X2 AntiAliasing - Evolva (D3D)

The performance drops drastically with FSAA enabled. This is where overclocking can yield very tangible results.

2x2 AntiAliasing - Quake 3 Demo001 (OpenGL)

We get very similar results in Quake 3. If you want reduce the jaggies, you'll have to compromise and get by on roughly 1/3 of the usual framerate. This should still be more than enough for most games, but the hardcore gamer will most likely decide in favor of high framerates. Besides, the image seems to become a bit softer, fuzzier with FSAA enabled.

Copyright: 09.12.2000 -   RIVA Station 2000 - Lars Weinand
No Copy without Permission!

Translation by Benjamin Kraft!

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