The Voodoo 5 does not fit on Pentium 4 boards
As Ace's Hardware reports, it is apparently not possible to plug the 3dfx Voodoo 5 AGP onto a Pentium 4 motherboard. This problem has already been observed on various motherboards.
The reason for this lies in the design of the Voodoo 5. The i850 chipset used on all Pentium 4 motherboards supports AGP 4x Pro and requires a cutout via pin 42-45 according to Intel specification The Voodoo 5 only has this via pin 22-25, as prescribed by the AGP 2x specification (3.3v I/O). While other graphics card manufacturers have equipped their AGP 4x graphics cards with two recesses according to AGP 2x and AGP 4x specifications (1.5v I/O and 3.3v I/O), 3dfx has so far dispensed with, which means that a Voodoo 5 can be plugged into one Pentium 4 becomes impossible. 3dfx itself makes the following statement:
They are fully compatible with all AMD and Intel processors, including Intel's new Pentium 4. However, our current boards are not compatible with AGP 1.5 Volt ONLY connectors. This connector provides 1.5 volt signaling to the socket and is physically keyed differently to prevent other AGP boards that required 3.3 volt signaling from being plugged into the AGP 1.5 volt only sockets. Unfortunately, the core logic chip for Intel's Pentium 4 does not support 3.3 Volt signaling on the AGP bus.