GeForce + Voodoo2 (not the original Voodoo Graphics card due to speed-sensitivity problems with that computer), you don't have to deal switching between AGP and PCI for the primary card and the Voodoo2 always gets treated as a secondary adapter in D3D games. This has a trade-off regarding the VGA passthrough which the output quality varies on the cable.

Between the two GeForce cards, will you be playing games that uses SM2.0 and 3.0? If not, then get the GeForce FX 59x0.

I've 2 rigs.
GF4 MX paired with Voodoo 2 SLI
GF4 Ti paired with Voodoo 3 2000 (with 2 screens attached)

I prefer a voodoo card without 2D support, just makes everything much easier. Glide will always goto the Voodoo everything else to your AGP card.

The other system plays mostly well. AGP card is set to Primary in BIOS so any non glide game will default to AGP. Not many games allow you to select the secondary card (in my case the V3) Gluide will always output to the Voodoo.
Only 1 game doesn't like this setup (Poweslide) for this I have to disable the AGP card in Device Manager and reboot, so not massive problem. but it's more messing round then the top system so I just don't.

I also have a system with GF6800 Ultra and never use it, lots of games work fine but nothing in Win98 needs the extra grunt and incompatibility means I don't use that rig much.
I like the idea of using the 3DFX card when you hit the compatibility issues though. Powerstip or whatever may work, or just disable it in Device Manager like I do.

Gmlb256 wrote on 2023-11-20, 01:08:

not the original Voodoo Graphics card due to speed-sensitivity problems with that computer

That part is interesting. Could elaborate a little?
Another (than I previously mentioned) reason that I am leaning towards GeForce 6800 is the fact that it is easier to get, cheaper and more powerful. I found not a bad deal on GeForce 6800 LE (which is the weakest 6800 but still more powerful than FX 5950 Ultra) which can be probably BIOS modded to higher 6800 (and if not then there is also software modding/unlocking pipelines and overclocking). Also it would be fun to push Windows 98SE/ME to limits and max resolutions, frame rates, use max AA and filtering and also maybe experiment with DirectX 9 games (which are no go on FX series) and KernelX (for that 6800 is definetely better and real full DirectX 9.0c helps and not that poor DirectX 9 implementation in FX series). Potential drawbacks with older titles should be covered with Voodoo. That's the plan at least for the moment. I hope that my reasoning is corect and that it makes senses and that it could work that way. All infos and suggestions are welcomed.

Sephiroth, The Great wrote on 2023-11-20, 02:42:

Gmlb256 wrote on 2023-11-20, 01:08:

not the original Voodoo Graphics card due to speed-sensitivity problems with that computer

That part is interesting. Could elaborate a little?

With a CPU faster than 400-500 MHz, the DOS Glide libraries for the Voodoo Graphics card has initialization problems, mainly being stuck on black screen or displaying a distorted screen. Its D3D support, which is a part to deal with potential drawbacks, isn't better with texture corruption problems.

I will be getting all cards (Voodoo 2, GeForce FX 59x0 and GeForce 6800). I want to test both variants: GeForce FX 59x0 + Voodoo 2 (SLI) and GeForce 6800 + Voodoo 2 (SLI). What (games) should I test to see which setup is better/more versatile? Should GeForce be also connected to monitor or only Voodoo?

1st/top slot (AGP) is GeForce 6800 LE (still waiting for FX 5900 to arrive).
2nd slot (PCI-E) is GeForce GTX 570 (580 is too big) and will be used for Windows 2000/XP (x64). Currently taken out when testing Windows 98SE/ME to give more air for others.
3rd slot (PCI) covered by GTX 570 and can't be used.
4th slot (PCI) Voodoo 2 12MB.
5th slot (PCI) is waiting for me to grab another Voodoo 2 to do SLI.
6th slot (PCI) Audigy 2ZS sound card.
I am kinda worried about cooling it and how will it work when everything would be connected. GTX 570 completely blocks fans of the above GeForce 6800 LE.