3dfx Voodoo Graphics

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Diamond Monster 3D.

The Voodoo Graphics (also "Voodoo 1") (code name SST-1) is a 3D graphics chipset introduced in October 1996 by the former Californian company 3dfx Interactive . It is considered to be the first usable 3D graphics chip in the non-professional area. In the professional sector, such as CAD, graphic adapters based on the TIGA or 8514 / A standard were used in the past .

history

Even before Voodoo Graphics, Nvidia presented the NV1, a 2D / 3D graphics chip, which, however, worked with curved surfaces , which did not meet with much approval from developers.

After about two years of development, 3dfx Interactive presented the Voodoo Graphics in October 1996 . Unlike the nVidia NV1 , this was a pure 3D chip without 2D functionality and used the triangle as the standard primitive. Similar to the PCX1 from PowerVR , it only offered a 3D unit and required a separate 2D card in the same system. Compared to later 3D accelerators and the 3D graphics workstations common at the time, these early graphics accelerators only contained the rasterizing unit, which takes on the task of filling the frame buffer . The matrix multiplications required for the projection of 3D coordinates onto the two-dimensional image surface and the lighting calculations were still carried out on the host CPU. The first 3D accelerator card with a working Transform & Lighting unit was the NVIDIA GeForce 256 , which was introduced at the end of 1999 .

In 3D applications (e.g. computer games) the accelerator card takes on the tasks of graphic calculation. This had the great advantage that the reduced workload on the main processor placed lower demands on the computer system. Even systems with processors that were relatively weak at the time (from Intel Pentium with 90 MHz and 32 MB RAM) could benefit from significantly accelerated and, above all, embellished 3D graphics - provided that the application was used - thanks to Voodoo Graphics.

The usual resolution in computer games with 3D graphics for the PC at the time was usually limited to 320 × 200 pixels . With the additional 3D accelerator card, resolutions of 640 × 480 pixels with impressive image improvement were smoothly playable. For this it was necessary to adapt the games to the hardware . 3dfx Interactive provided the programmers with the in-house interface Glide . However, since the improvements that could be achieved were immense, the corresponding patches were not long in coming. I.a. Descent II, Quake and Tomb Raider were among the upgraded computer games. The graphic interfaces OpenGL and Direct3D that were already in existence at the time were also supported.

The first 3D accelerator cards with the Voodoo Graphics cost around 370  DM .

Wiring (Voodoo above, graphics card below)

installation

A 3D accelerator card equipped with the Voodoo Graphics is connected to the 2D graphics card with an analog loop cable ; the monitor is also connected to the 3D accelerator card. Installed in this way, the signal coming from the 2D card (e.g. the display of a command line or the Windows desktop) is looped through the loop cable to the monitor.

However, this construction can lead to a loss of quality in 2D mode at (then) high frame rates and resolutions (from around 1280 × 1024 pixels). PowerVR therefore pursued a different concept via the PCI bus, which, however, required significantly more powerful motherboards .

The two chips on top of each other represent PixelFX and TexelFX.

properties

Almost all (for exceptions see below) cards with the Voodoo Graphics are equipped with 4 MByte 50 MHz EDO memory. Due to a dual-channel memory connection with 2 × 64 bits, which was unusual for the time, 2 MB frame buffers were reserved for the pixel processor called PixelFX and 2 MB texture memory for the texture processor called TexelFX. The standard clock is 50 MHz.

The specified fill rate is 45 megapixels (or 45 megatexels). For comparison, the GeForce 2 GTS , released in 2000 , was the first graphics card to break the 1 gigapixel limit. The RAMDAC of the Voodoo Graphics is 135 MHz. When using the Z-buffer , a resolution of 640 × 480, otherwise 800 × 600 at 85 Hz, could be achieved. This is done with a color depth of 16 bits; the 65,536 colors that can be represented in this way were revolutionary at the time.

(The following list was taken from the technical manual.)

In contrast to current (2013) graphics cards, the Voodoo only processes the last part of the rendering pipeline, namely the rasterization including texture mapping of triangles in the screen coordinate system . Modern graphics cards also take over the transformation of the geometry and the clipping.

Diamond Monster 3D with loop-through cable

Well-known 3D accelerator cards with Voodoo Graphics

  • Diamond Monster 3D (4 MB)
  • Guillemot MaxiGamer 3D (4 MB)
  • Orchid Righteous3D (with this card you could hear a click when switching to 3D display mode because a mechanical relay was used)
  • Miro Highscore 3D and the identical Canopus Pure 3D (6 MB graphics memory; the additional 2 MB are additional texture memory)
  • VillageTronic MacMagic (8 MB total memory, 4 MB image and texture memory each)
  • Quantum3D Obsidian 100SB 4440/4400 ( SLI card with 20 or 12 MB total memory, the first version has a second TMU like the Voodoo2 chipset)

Software emulation of the 3dfx Voodoo Graphics

There is a patch for the DOSBox emulation software that emulates the Voodoo Graphics 3D accelerator on the software side.

Footnotes

  1. ↑ Official reference to the SST-1 (PDF; 1.4 MB)
  2. ↑ Strictly speaking, this is not about trilinear filtering, but rather MipMap dithering, which produces a similar result.
  3. ↑ Voodoo-Graphics-SW-Emulation for the DosBOX