If you don't play games on your Mac, this section is probably not for you. However, If you do play 3D games (Quake, Unreal, Carmageddon, etc.) on your computer, you need one of these cards. The difference in image quality and detail that one of these cards makes is unbelievable! After playing with one, you can't play without it. The card (if it gives only 3D support) sits idle in one of your PCI slots untill it is called upon to by a program that uses Glide (3Dfx) or Rave. The card is connected via a cable directly to the moniter and has pass-through cable that connects to the normal monitor out port of your Mac (if it doesn't have its own 2D support). This pass-through cable allows the computer's internal video card (w/ VRAM) to display 2D graphics when the 3D card is not active. If the 3D card does not have 2D support, it only does full screen 3D (not in a window). If it has 2D support, it might be able to do 3D in a window. You should have a PowerMac to use a 3D graphics accelerator. Some come with one pre-installed.
If you want to buy one, the choice you have to make is whether to buy a 3Dfx Voodoo2, 3Dfx Banshee, or a ATI Nexus Rage. The Voodoo2 and Banshee use the same 3D chipset but the Banshee also come with 128-bit 2D support (the Voodoo2 is only 3D). The Nexus Rage uses a different chipset and supports both 2D and 3D. The Voodoo2 does only full screen 3D while the Nexus and the Banshee can do 3D in a window and full screen. Voodoo2's use Glide by default, but can also use Rave if that is the only type a program supports (most 3D programs will support both Glide and Rave). ATI's use Rave by default but have no problem using Glide. For both types of cards you should have the latest drivers (System extensions) that are provided by the manufacturer. All 3D cards have their own built in memory; the more memory, the better (ATI's tend to have more). Here is a quick comparison of the 3 cards:
Voodoo2
Cheaper because there is no 2D support. It come with a pass-through cable.
12 MB model for PowerMac & 8 MB model for iMac
Only full screen 3D
I own one and it works great
Buy 12 MB model - click for price and info. A word of caution: I believe that the company, Micro Conversions, went out of bussiness, so any items of theirs that you buy may be unsuported.
8 MB model - unavailable.
Banshee
Cheaper than a Rage because it has less memory (16 MB)
More expensive than a Voodoo2 because it supports 2D (128-bit) and 3D
Can do 3D in a window
Is slower (fps) than a Voodoo2 when doing full screen
After you purchase a card, you can check here for installation instructions. Note for iMac users: None of these cards can be used by you except for the 8 MB Voodoo 2 Game Wizard. However, this card can only be used on the original iMac and Revision B iMac with a Mezzanine slot. It can not be used on revision C iMacs.