3dfx (written as 3Dfx until 1999) was a 3D graphics chipset manufacturer and later on graphics card manufacturer. Founded in 1994, the company was one of the pioneers of 3D graphics in the PC industry in the mid to late 1990's. They played an important role in the business until 2000, when most of their assets were purchased by Nvidia Corporation, after which the company filed for bancruptcy and officialy went defunct in 2002.
The Voodoo Graphics (retroactively named Voodoo 1) chipset was 3dfx' first foray into the PC market. Its release in 1996 was primarily made possible by EDO DRAM declining in price. The cards, which were manufactured by board partners, feature a frame buffer processor, a texture processor, a DAC and 4 MB EDO DRAM (some later versions were released with 6 or even 8 MB). Both the RAM and graphics processors operate at 50 MHz, with 2 MB RAM being used as framebuffer and 2 as texture memory. The chipset was rich in features, boasting perspective correct texture mapping, bilinear texture filtering, level of detail MIP mapping, sub-pixel correction, polygonal-based Gouraud shading and texture modulation. It natively supported Direct3D 5 and introduced Glide, 3dfx's own proprietary API that worked initially under DOS and later under Windows 9x and NT 4.0/2000/XP. Glide was essentially a cut down OpenGL implementation, with no support for features such as 32-bit color depth. OpenGL games were initially only supported through the use MiniGL, which were incomplete OpenGL implementations tailored for the particular target card and game; the best example of this was GLQuake, which offered better image quality and over twice the resolution compared to the commonly used 320x200 in regular software rendered Quake, all at similar framerates. In 1999, 3dfx released a full OpenGL ICD, thus finally granting native support for OpenGL games, which was becoming more and more important since full OpenGL support was required for the then-upcoming Quake 3.
The main disadvantage of the cards was that they could only do 3D, meaning that they had to be used in conjunction with a standard 2D card through means of a passthrough cable. During boot and regular PC operation the 2D card would display the image like usual and run the signal through the Voodoo; however, when a compatible game was ran, the Voodoo Graphics would be enabled, taking over the host card. Combinations with S3 Graphics cards, as well as Matrox cards were quite popular. Unfortunately, the passthrough method was very dependent on the build quality of the used cable and could potentially lead to blurriness.
Thanks to 3dfx's efforts with videogame developers and publishers - the company's technology was quickly adpoted as the de-facto standard in PC 3D gaming - the Voodoo 1 enjoyed a lengthy support from game developers. Despite only supporting resolutions as high as 640x480 (800x600 without the usage of Z-buffering) and 16-bit depth, the card was more or less usable until 1999, when its performance in new games would have been slow.
The prime competitors upon its release were the PowerVR PCX1 and Rendition Vérité V1000 chipsets, the later of which already featured 2D processing onboard. Other competitors include the Matrox Millenium II/Matrox Mystique, ATI Rage II, S3 Virge and Nvidia RIVA 128, all of which had 2D functions, but only the RIVA 128 can be said to match the Voodoo 1 in performance, while of course lacking Glide support.
Today: The card's prime usage would be statically linked Glide games in DOS that depend on the first Voodoo chipset. Later games, starting with ca. 1997, are better played with the subsequent Voodoo cards.
Voodoo Rush was released in August 1997 and adressed the main shortcoming of the Voodoo Graphics by being a complete 2D/3D solution. The chipset combined either an Alliance Semiconductor AT25/AT3D or Macronix 2D core on the same board as the exact same Voodoo chipset (on some cards the 3dfx part came as a daughterboard).
Unfortunately the combination of two independent chipsets led to a bottleneck for the 3dfx part and therefore about 10% lower performance. Some later cards had 6 or even 8 MB and somewhat higher clocks to close this gap. The cards also sometimes weren't fully compatible to existing games, leading to specific Voodoo Rush patches for some games, e.g. Tomb Raider.
It is interesting to note that the AT3D chipset actually has very rudimental 3D functions which can be activated, meaning that Rush cards that feature it have two 3D chipsets.
Today: Rush cards are widely considered an infamous early attempt at a 2D/3D card by 3dfx and should be avoided when building a vintage gaming system.
Released in early 1998, the Voodoo 2 chipset expanded upon its predecessor by adding a second texture processor and featuring 12 or 8 MB EDO DRAM. The clock was increased to 90 MHz, therefore almost doubling the performance. Since the V2 features single-pass multitexturing and single-pass trilinear filtering (and therefore supports Direct3D 6), performance in games utilizing these features is even more increased, with the first notable one being Quake II (1997). Additionally, the cards support SLI (Scan-Line Interleave), a technique which allows 2 cards to be run simultaneously and draw the lines of the image in turn, further increasing performance and enabling resolutions up to 1024x768. With one card installed, up to 800x600 is possible.
A large amount of cards from different manufacturers was released, with some deviating from the reference design and/or featuring extra cooling and even slight factory overclocks. The Voodoo 2 remained the best 3D accelerator card throughout 1998.
Today: The iconic Voodoo 2 SLI setup holds nostalgic value for some people that experienced it back in the day. Thanks to the PCI interface, they can theoretically be used even in some modern mainboards, although there are rumors of them overheating in modern systems. In any case, the setup remains viable for the vast majority of Glide games released and can even play some Glide games originally only designed for Voodoo 1 through a special batch file, although for later games, the newer cards have to be considered superior.
Released in 1998, the Banshee was 3dfx' second attempt at a full 2D/3D card. This time, they integrated a 2D core, a single-TMU Voodoo 2 and the DAC into one chip and clocked it at 100 MHz, meaning that the midrange Banshee was actually slightly faster in prevalent single-textured games than the high-end Voodoo 2. In games utilizing multitexturing, such as Quake II and Unreal, the Banshee showed clearly inferior performance compared to the V2.
Due to better integration the chip outputs more heat and therefore all cards came with some kind of cooling solution. They featured 8MB/16MB SDRAM or SGRAM and came in PCI or AGP versions.
Its 2D acceleration was the first of its kind from 3dfx and was very capable. It rivaled the fastest 2D cores from Matrox, Nvidia, and ATI. It consisted of a 128-bit 2D GUI engine and a 128-bit VESA VBE 3.0 VGA core. The graphics chip capably accelerated DirectDraw and supported all of the Windows Graphics Device Interface (GDI) in hardware, with all 256 raster operations and tertiary functions, and hardware polygon acceleration. The 2D core achieved near-theoretical maximum performance with a null driver test in Windows NT.
Today: Although much better cards than Voodoo Rush, Banshees should be avoided for the most part, because of the suffering performance in more demanding games from the era. For DOS only operation or less demanding games, it can still be somewhat worthwile.
The Voodoo 3, codenamed Avenger, was announced on COMDEX in November 1998 and released on April 3, 1999. Following the buyout of STB, 3dfx was now manufacturing their own cards. The Voodoo 3 was basically a higher clocked Banshee core outfitted with a second texture unit, therefore also incorporating the 128-bit 2D unit. The cards were released in four different flavors: the 125MHz Voodoo 3 1000, the 143MHz Voodoo 3 2000, the 166MHz Voodoo 3 3000, and the 183MHz Voodoo 3 3500 TV with integrated TV tuner. Aside from the lowest-end part which could come with either 8 or 16 MB of memory, all cards featured 16 MB of SDRAM, with some PCI cards instead having SGRAM. The maximum resolution is 2048x1536.
Now facing stronger competition from Nvidia's RIVA TNT line, which already had 32-bit color depth, higher than 256x256 texture support and AGP texturing support (all 3dfx cards use the AGP port as a mere 66MHz PCI port), the Voodoo 3 line was somewhat panned by critics and called outdated in terms of features, but was still considered to be very competitive speed-wise, because 32-bit rendering introduced a big performance hit on competitor cards. At that time, 3dfx' marketing was centered around speed, but to demonstrate that the image quality was still better than their last year's high-end setup, they invented the term "22-bit", describing the fact that the RAMDAC of the card would perform either a 2x2 box or 4x1 line filter on the image, depending on the driver settings, masking some of the dithering.
The GeForce 256, which came out later that year, beats it both by features and performance in D3D and OGL games, but can merely tie it in some Glide-centric games such as Unreal Tournament.
Today: A Voodoo 3 2000 roughly matches Voodoo 2 SLI 12MB in speed, while possibly still offering better real-world performance due to 4 MB more texture memory. Like with all Voodoo cards, the cards will run games requiring 8-bit paletted textures or table fog. If all this is taken into account together with the card's good DOS compatibility, speed, wide availability and low cost, the Voodoo 3 can be considered the all-around best "retro" card for games of its time frame and before.
Voodoo 4/5 (VSA-100)
The VSA-100 (Voodoo Scalable Architecture) was the final product from 3dfx and was released in 2000. Only the single-chip Voodoo 4 4500 and the dual-chip Voodoo 5 5500 made it to the market, both clocked at 166 MHz. It was a further refinement of the architecture of all previous products, with some changes and additions such as two pixel pipelines with one texture unit each (instead of one pipeline with two texture units), 32-bit rendering and larger texture caches. The chip supports 2048px x 2048px textures, FXT1 and DXTC texture compression. Additionally, 3dfx's marketing was now more centered on image quality ("cinematic effects") than speed: Due to the added "T-buffer" the Voodoo 4 4500 can do 2x RGSSAA (rotated-grid super-sampling anti-aliasing), while the Voodoo 5 5500 is capable of 4x RGSSAA. This method of anti-aliasing is considered high quality until today and was actually usable in a large number of titles with good performance. The Voodoo 5 is comparable with Geforce 256, but was not competitive with high-end GeForce 2 cards, especially since Glide support in new games was rapidly declining by that time. Unlike the GeForce cards which were Direct3D 7 capable, the VSA-100 line was still limited to Direct3D 6, as it lacked Hardware T&L. This feature was slowly taking off in 2000 and games from that time which use it are not optimally suited for these cards.
Voodoo 5 5500 cards have 64 MB SDRAM, although only 32 of it are actually usable due to the SLI method used, much like with Voodoo 2 SLI. They require a 4-pin Molex adapter.
Today: Being the last cards from 3dfx that made it to the market, both come at a premium. The V4 4500 is arguably not a much better card as the V3, since it scores similarly to a V3 at same clocks and trails higher clocked V3 parts, with the added features not playing a big role here. The V5 5500 is considerably faster and provides an optimal Glide experience up to around 1280x1024, with the added possibility of adding AA. It is commonly used with Athlon XP systems today, because it scales relatively well with faster CPUs.