Cable to your display is a must. There are various ways how glide games threat Voodoo - from hard coded to optional.

Voodoo3 is NOT a 3d add-on card like a voodoo1 or voodoo2 so it also does not ''pass trough'' the signal to the agp card.

It needs to be used as a full blown graphics card: for 2d, direct3d and glide.

You can switch cards in the bios (selecting pci or agp card first) and let windows load the driver for the card you chose. You also have to switch the monitor cable if you switch cards, or you can use a monitor switch/kvm switch. When there is no big important reason to use an agp card it is much easier to just have the v3. It is a nice card for most retro games.

If you want it all you can use the agp and have one or two voodoo2 cards at the same time. This is one of the reasons voodoo2's are so popular. These are add-on cards that let you use your agp for direct3d if you want to and can be used to play glide (they also support direct3d and you can select the agp or the v2's for direct3d). This is not possible with a voodoo3.

Some games you get a menu, other games have a different executable for the glide version. It all depends on the game.

agree with the above.

Theoretically you could use an AGP (T&L) card with a V3 PCI in a dual display setup while only using 1 monitor (condition is the monitor has both DVI + VGA input).
If the AGP card has a DVI output you can connect a DVI cable to DVI input monitor and the VGA output from V3 to VGA input monitor. I tested this and some games seem to be able to switch to the V3 when selecting Glide API but unfortunately multiple display support on W98SE works quite awkward.

So really your best option is to make a dedicated V3 setup or alternatively switching the Primary Display adaptor in the BIOS.

The Voodoo 3 is a great 2D/3D card for retro gaming. It rocks from 199x-2000. I use my retro PC more for gaming then my modern PC. 🤣

Plus, you can overclock that V3 2000 to 3000 or 3500 speeds no problem with a simple fan mod.