The 4500 and the 5500 use the same VSA-100 GPU, although the 5500 has two of them. I tried a 5500 in my A4000D since I had one around, but I didn't see any performance increase over the Voodoo3 3000 so I took it back out. The added benefit of less noise, heat and power consumption helped the decission. (Beware the 4500 shouldn't suffer from most of these, it's a smaller card, without an external power requirement)
