If you were to use an original 3dfx Voodoo3 2000 card (or I believe any of the Voodoo series of cards), you can flash the PC version for use on the Mac. I've done it and it works perfectly. Apparently, 3dfx didn't think that people would realize that they were actually selling the same card flashed for the Mac to Mac users at a higher price than the PC version. So then Mac users started buying the PC version and flashing it for the Mac. Of course, this card had the same firmware space on both cards so there was enough space for the Mac firmware to be installed to it.
Because of this, vidcard manufacturers got smart and started only including the amount of ROM size enough for a specific platform. So the Mac versions actually had more ROM space than the PC version, which helped prevent this practice. Of course, this hasn't stopped people from doing this, but the results aren't the same anymore (instability at best, instant-doorstop at worst).
ATI now is selling a card that comes with PC and Mac support right out of the box, so you don't even need to worry about whether it works in a specific platform. YEs, it's a little more than jsut the PC version, but you assured that it works on both platforms. I'm hoping that more video card manufacturers take on this practice, especially with Apple becoming more mainstream than it has ever been, IMO.
