Voodoo 5

The Voodoo 5 was the last and most powerful graphics card line that 3dfx Interactive released. All members of the family were based upon the VSA-100 graphics processor. Only the single-chip Voodoo 4 4500 and dual-chip Voodoo 5 5500 made it to market.

The VSA-100 graphics chip is a direct descendant of "Avenger", more commonly known as Voodoo3. It was built on a 250 nm semiconductor manufacturing process, as with Voodoo3. However, the process was tweaked with a 6th metal layer to allow for better density and speed, and the transistors have a slightly shorter gate length and thinner gate oxide. VSA-100 has a transistor count of roughly 14 million, compared to Voodoo3's ~8 million. The chip has a larger texture cache than its predecessors and the data paths are 32-bits wide rather than 16-bit. Rendering calculations are 40-bits wide in VSA-100 but the operands and results are stored as 32-bit.

One of the design goals for the VSA-100 was scalability. The name of the chip is an abbreviation for "Voodoo Scalable Architecture." By using one or more VSA-100 chips on a board, the various market segments for graphics cards are satisfied with just a single graphics chip design. Theoretically, anywhere from 1 to 32 VSA-100 GPUs could be run in parallel on a single graphics card, and the fillrate of the card would increase proportionally. On cards with more than one VSA-100, the chips are linked using 3dfx's Scan-Line Interleave (SLI) technology. A major drawback to this method of performance scaling is that various parts of hardware are needlessly duplicated on the cards and board complexity increases with each additional processor.

3dfx changed the rendering pipeline from one pixel pipeline with twin texture mapping units (Voodoo2/3) to a dual pixel pipeline design with one texture mapping unit on each. This design, commonly referred to as a 2x1 configuration, has an advantage over the prior 1x2 design with the ability to always output 2 pixels and 2 texels per clock instead of 1 pixel and 2 texels per clock.

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