The first AGP video card I ever owned was a Voodoo3 3000... which of course wasn't actually a "real" AGP card, really just a PCI card with an AGP bridge chip. The Voodoo3 was a funny animal,. For running GLIDE (or the subset of OpenGL that mapped directly to glide) it was fast by pre-GeForce/Radeon standards but there was a lot about its internal architecture that was weird and brain-damaged, such as the 3D renderer *only* working in 16bit mode and being limited to relatively tiny texturemaps. (Oddly enough its 2D accelerator was *very* fast and worked fine with a 32 bit framebuffer.) Assuming your B&W came with the standard ATI Rage 128 it is by most measures at least a comparable card to a Voodoo3, even if you limit the comparison to things the Voodoo3 does well. It's hard to find period benchmarks anymore but they usually show the Voodoo3 being about 20-30% faster than a Rage 128 at 16 bit color depth. However the 128's hidden talent is it hardly slows down at all going to 32 bit color which a Voodoo3 cannot do *at all*.

(I'm harping on the Voodoo3 because I think it's pretty unlikely we're talking about a Voodoo5 here. They're not *incredibly* rare but they are scarce. The Voodoo5 is roughly on the same level as the original Radeon card but has completely miserable driver support... and has the additional limitation that it won't perform much better than a Voodoo3 unless the game in question works well with SLI, which was needed to spread the load over its multiple graphics processors.)