As far as I remember, the PCX series should be compatible with 5x.xx drivers (maybe you should modify .INF in driver), at least some of them. Yes, it is more compatible with Windows 9x games than 6 series in general, although it falls a short of AGP FX cards.

Unless there's at least one PCX card officially listed in ForceWare 5x.xx, changing INF won't help - no HSI bridge information. I doubt that NVS 280 with integrated HSI bridge came before any card with a separate HSI bridge.

AaronS wrote on 2025-09-01, 15:56:

I'm trying to find an ideal Nvidia card for Windows 98 for a more modern board that has no AGP, so PCI or PCI Express. I've read […]
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I'm trying to find an ideal Nvidia card for Windows 98 for a more modern board that has no AGP, so PCI or PCI Express. I've read that the PCX FX cards cannot go below 6x.xx which is past the point of compatibility with a number of titles, and I think these were the earliest PCIe Nvidia cards. However having a look at techpowerup I found that the NVS 280 had a PCIe release (NV37), which may be compatible with 56.64 at least. Has anyone any experience with this card?
https://www.techpowerup.com/gpu-specs/quadro- … -280-pcie.c1456

I have a 6800 currently which works amazingly well but I prefer something a bit older and more compatible. PCI FX 5500 is probably what I'll end up going with since they're more available, but quite pricey.

EDIT: Hmm actually maybe not, the PCX FX 5900 is NV35 and according to nvidia driver installation inf the earliest mention of it is 61.76
https://www.techpowerup.com/gpu-specs/geforce-pcx-5900.c56
https://www.philscomputerlab.com/nvidia-9x-gr … cs-drivers.html

I suppose you would get 8 bit palleted textures but otherwise there's no real benefit over a 6000 series.

I wasn't able to get any drivers earlier than 6X.XX (can't remember which ones) working on Quadro FX 1300 and PCX 5750. Even then they didn't work well with Nvidia control panel errors and flashing issues in games.

Dothan Burger wrote on 2025-09-01, 20:24:

I wasn't able to get any drivers earlier than 6X.XX (can't remember which ones) working on Quadro FX 1300 and PCX 5750. Even then they didn't work well with Nvidia control panel errors and flashing issues in games.

I see, thanks for the info. I guess I could try it on the NVS 280 PCIe if I find one cheap (there's quite a few on ebay in the US), but I'm sure it'll be the same situation. I'll get a PCI FX card down the road then.

AaronS wrote on 2025-09-01, 20:33:

Dothan Burger wrote on 2025-09-01, 20:24:

I wasn't able to get any drivers earlier than 6X.XX (can't remember which ones) working on Quadro FX 1300 and PCX 5750. Even then they didn't work well with Nvidia control panel errors and flashing issues in games.

I see, thanks for the info. I guess I could try it on the NVS 280 PCIe if I find one cheap (there's quite a few on ebay in the US), but I'm sure it'll be the same situation. I'll get a PCI FX card down the road then.

I think going the PCI route is your best option. Even when the PCX cards work I had strange issues with input lag.

Dothan Burger wrote on 2025-09-01, 21:34:

I think going the PCI route is your best option. Even when the PCX cards work I had strange issues with input lag.

Input lag is most likely a compatibility issue with new Intel chipsets.

The Serpent Rider wrote on 2025-09-04, 18:03:

Dothan Burger wrote on 2025-09-01, 21:34:

I think going the PCI route is your best option. Even when the PCX cards work I had strange issues with input lag.

Input lag is most likely a compatibility issue with new Intel chipsets.

I've tested on i915, 945 and P55. edit: I'm going to build an AM3 system to test if your hypothesis is right.