The motherboard revision isn't an issue when upgrading the graphics card. The card that you select must be Mac-compatible, meaning that it has a Mac ROM. Various "PC" graphics cards can have their ROM chip flashed to function in a Mac, provided that you have the necessary firmware. If you search the web for info about flashing graphics cards, you'll see what's involved.
The motherboard revision isn't an issue when upgrading the graphics card. The card that you select must be Mac-compatible, meaning that it has a Mac ROM. Various "PC" graphics cards can have their ROM chip flashed to function in a Mac, provided that you have the necessary firmware. If you search the web for info about flashing graphics cards, you'll see what's involved.
Oh ok - I know nothing about this - can this specific graphics card be flashed to work on a B&W G3? Does it just need to be flashed to work on the mac? or will it need specific firmware for my B&W G3? Thanks for your help
I did flash a Matrox Millennium II PCI card in order to make it Macintosh compatible, but the flashing process failed and the card is unusable. In that specific case, some Matrox cards have sufficient ROM size, or not.
There are also other issues related to flashed graphic adapters, like color fidelity, which is not so good in some situations.
I would advise to flash old hardware only for the fun of it, and to practise a bit the computing lore.
From a practical viewpoint there are excellent upgrade solutions like the ATI Radeon 7000, or the standard ATI Rage 128, which is good for everyday stuff. On the adventurous side, you can also chase for older cards like the Imagine 128 which was incredibly good back in 1997-98.
Of course, everything I say is based on my personal experience, and use of Macintosh stuff for work, not for fun or games.
The firmware is not model-specific, because it enables the use of the card in any Mac that meets the card's requirements. With some of the latest cards, the additional power consumption is an issue, given the available output of the power supply. As Frederic has indicated, if a card doesn't have an adequately-sized ROM chip onboard, the Mac firmware may be too large for it and the flash fails. As a workaround for this situation, some hackers have created truncated ROMs for such cards. The flashing process is usually done, while the card is installed in a PC. A few years ago, I flashed about (8) ATI-built Radeon 7000 cards, and haven't had problems with any of them. As you may have discovered, ATI licenses the use of its Radeon graphics chip to third-party companies, which market cards that are "Powered by ATI," and not "Built by ATI." If you search the web for "flashing graphics cards," you'll find some web sites with in-depth discussions of the process. There are certain Radeon 9250s that can be flashed, depending on which company's card you're using.