I've been working through similar issues with early PCI 486 boards, Via and Intel 420EX chipsets ( PCI 2.0 Support)

So far it seems like a lot trial and error. Here's the rules I have so far:
[*] video cards built after 1997 probably won't work in a PCI 2.0 motherboard
[*] hard drive controllers after 1996 that want to do bus mastering are unlikely to work reliably in a PCI 2.0 motherboard
[*] cards with a 3.3V notch are unlikely to work in a PCI 2.0 motherboard

I've tested the same cards in 430VX & 440BX boards and they have very good compatibility, but they have PCI 2.1 support.

You probably don't have a 430LX board.

You are working with a 440NX or a 440FX board? They are both listed as only having PCI 2.0 support

https://en.wikipedia.org/wiki/List_of_Intel_chipsets

Thanks for the information! It is helpful to hear another perspective.

The computer I'm working on is a P90 Compaq Deskpro and neither the main motherboard nor the separate processor/RAM card have any ICs clearly branded as Intel. Therefore I cannot discern the chipset. Not sure what to make of that vs. the Wikipedia entry suggesting one of these chipsets should be present?

In any case I do have another data point to add... a Matrox Millennium II PCI 4MB works perfectly in the computer. It does not have the second PCI notch.

Always happens. I eventually got all the PCI video cards that works partially working perfect on TX motherboard. Goes down to the bios and/or chipset PCI version support.
I knew HX and TX is PCI 2.1 but it was the early HX motherboard with very limited bios, well known Micron ATX with HX chipset and would only report 200MMX even I had 1.5x set for 233mxx, still says 200MMX, also would not initialize some of the video cards I have on hand. Then I got my hands on a Intel AN430TX motherboard and this worked perfectly.

Cheers,

OT, but I have a Pentium II Xeon machine from 1999 that went completely berzerk when I plugged in a GeForce 8400 GS card. Among other things it scrambled the hard drive forcing me to reinstall Windows.

Another reference, I received a Millennium 4MB PCI card and like the Millennium II, it works fine as well. Furthermore, to my great surprise, it is 5% to 15% faster in DOS than the II model! In windows, GPU benchmarks such as Winbench show it somewhat slower in synthetic tests, but application tests like Winstone show equivalent performance. Really nice card, I wish I had one at the time.

A Rendition Verite V1000 card would be an interesting test subject. They released a DMA test utility because lots of motherboards are the time didn't have reliable PCI DMA transfers. The V1000 chips aren't exactly stable in general but flaky DMA transfers don't help.

Actually I'm not sure a card is even required to run their test program.
http://www.vogonsdrivers.com/getfile.php?file … &menustate=17,1