3dfx's Voodoo4 4500 AGP uses a single 166MHz VSA-100 with 32MB of 166MHz SDR SDRAM on a 128-bit memory bus. It has 2.7GBps of memory bandwidth. The VSA-100 can render up to two pixels per clock with one texture each, which yields 333Mpixels per second and 333Mtexels per second fill rates.

The VSA-100 has a feature called the T-Buffer (which you can read about in-depth in our 3dfx Next Generation Guide), which acts as an accumulation buffer. The T-Buffer gives developers the option to perform calculations on an image after it is sent through the graphics pipeline without having to send the data through again. T-Buffer effects include but are not limited to FSAA, depth of field, motion blur, and soft shadows. An unfortunate side effect of the Voodoo4 4500 only having one VSA-100 chip is that T-Buffer effects are diminished, in this case from 4x FSAA on the Voodoo5 to only 2x FSAA on the Voodoo4. This would tend to decrease the differentiation that 3dfx has been pushing as compared to their competition's FSAA capabilities.

The RADEON GPU, which is dissected in our ATI RADEON Guide, comes on two different cards in this roundup, the SDR and DDR versions. The SDR version is clocked at 160MHz with 32MB of SDR SDRAM running at the same 160MHz. The DDR version runs the GPU at 166MHz with 32MB of DDR memory also running at 166MHz (the equivalent of 333MHz SDR). With two pixel pipelines and three texture units, the RADEON can process up to six texels (textured pixels) per pass. That gives the DDR card 333Mpixel and 999Mtexel fill rates and the SDR card 320Mpixel and 960Mtexel fill rates. The transformation and lighting engine can render about 25 million polygons per second on both versions.

Like the GeForce2 MX, the RADEON also makes use of programmable pixel shaders. While the GeForce2 supports functions with two textures and two operations per clock cycle, the RADEON supports three textures and three operations per cycle. ATI has also incorporated a proprietary feature called HyperZ to save memory bandwidth on necessary calls to the Z-buffer, raising the effective fill rate. Four-matrix skinning and keyframe interpolation round off a feature-rich package, giving the RADEON the most hardware feature support for DirectX 8 of any current card.

Matrox uses a less powerful 3D engine than the competition. Running at 166MHz with 32MB of 166MHz DDR SDRAM (333MHz SDR SDRAM equivalent) on a 64-bit bus, the G450 has 2.7GBps of memory bandwidth. The G450 core can process one pixel per clock with two textures per pixel, which gives it 166Mpixel and 333Mtexel per second fill rates, the lowest in the roundup. The G450 also comes with dual-head VGA outputs, one of which can act as a TV-output as well.