There will be several iterations of the Voodoo4/5, each with a different number of VSA-100 chips, ranging from one to four running in SLI (Scan Line Interleave). The Voodoo5 5500 features two VSA-100 chips and has a total of 64Mb of 166MHz SDRAM, although both chips require their own texture memory, so some of the RAM is shared. As a result of the Voodoo5 5500 sporting two chips, it also has a higher than usual power requirement, which means you have to plug a power connector from your power supply into the card itself. The card is fairly long, and some might find it difficult to fit inside their case, although 3dfx says that the card conforms to the ATX standard.
Unfortunately the performance of the Voodoo5 was not up to that of the similarly priced GeForce2 GTS-based cards in either 3DMark2000 Pro or Quake III Arena. The Voodoo5 lacks hardware transform and lighting (T&L), which penalises it in 3DMark2000, although even with T&L disabled, the GeForce2 cards still outperformed the Voodoo5.
Considering the high price of the Voodoo5 5500, and its relatively average performance, it is hard to recommend it over a GeForce2 GTS. The upcoming Voodoo5 6000, with no less than four VSA-100 chips, should give nVidia something to worry about, but until then, the GeForce2 GTS maintains its title as fastest consumer graphics chipset available.