DaNi,
If I remember correctly the Voodoo 3000 Series were either PCi or AGP 16 MB Memory.
The Voodoo 5500 was one of the late Voodoo cards released was very power hungry AGP or PCI but rarely found as PCI and had 64 MB of RAM.
There is Mediator support for the later Voodoo cards but generally the 3000 series card are more frequently used.
Cheers
Shaf