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3dfx Voodoo¶

Released in 1996, the 3dfx Voodoo was a dedicated 3D-only accelerator — it handled nothing but 3D rendering. You’d install it alongside your regular video card and connect the two with a pass-through cable — a gloriously awkward arrangement that made your PC look like it was held together with good intentions. But the results were something else. Smoother geometry, bilinear filtering, atmospheric fog effects: things that simply weren’t possible on a CPU alone.

Games accessed the Voodoo through 3dfx’s proprietary Glide API, which talked to the hardware directly and unlocked effects that software rendering couldn’t touch. When a Glide game launched, the Voodoo took over the display entirely; quit to DOS, and the signal fell back to your 2D card. Titles like Tomb Raider and Screamer 2 were transformed by it. Even the fastest Pentium MMX machines could barely manage software-rendered 3D at 640×480 — we’re talking single-digit framerates. The Voodoo was a luxury, but what a luxury it was!

Most Glide games need a DOS driver file called GLIDE2X.OVL in the game’s directory. Many shipped with their own version of this driver; for those that didn’t, you’ll need to supply a suitable one (not all drivers work with every game).

DOSBox Staging emulates the Voodoo at the hardware level (no shortcuts or OpenGL passthrough), which makes it CPU-intensive but highly accurate. Voodoo emulation is enabled by default, so most DOS Glide games should work out of the box. If a game doesn’t use Voodoo graphics, there is not performance penalty whatsoever.

Complete list of DOS games with 3dfx Voodoo graphics support

Configuration settings¶

You can set the 3dfx Voodoo parameters in the [voodoo] configuration section.

voodoo¶

Enable 3dfx Voodoo emulation. This is authentic low-level emulation of the Voodoo card without any OpenGL passthrough, so it requires a powerful CPU. Most games need the DOS Glide driver called GLIDE2X.OVL to be in the path for 3dfx mode to work. Many games include their own Glide driver variants, but for some you need to provide a suitable GLIDE2X.OVL version. A small number of games integrate the Glide driver into their code, so they don’t need GLIDE2X.OVL.

Possible values: on default, off

voodoo_memsize¶

Set the amount of video memory for 3dfx Voodoo graphics. The memory is used by the Frame Buffer Interface (FBI) and Texture Mapping Unit (TMU).

Possible values:

  • 4 default – 2 MB for the FBI and one TMU with 2 MB.
  • 12 – 4 MB for the FBI and two TMUs, each with 4 MB.
voodoo_threads¶

Use threads to improve 3dfx Voodoo performance.

Possible values:

  • auto default – Use up to 16 threads based on available CPU cores.
  • <number> – Set a specific number of threads between 1 and 128.

Note

Setting this to a higher value than the number of logical CPUs your hardware supports is very likely to harm performance. This has been measured to scale well up to 8–16 threads, but it has not been tested on a many-core CPU. If you have a Threadripper or similar CPU, please let us know how it goes.

voodoo_bilinear_filtering¶

Use bilinear filtering to emulate the 3dfx Voodoo’s texture smoothing effect. This is enabled by default to match the look of real Voodoo hardware, which always applied bilinear texture filtering. Disabling it gives a sharper but less authentic look, and may help performance on slower systems.

Possible values: on default, off