https://dependency-injection.com/vlb-vga-group-test/ - look under Test Results - DOS
There isn't a dramatic difference between a "great" VLB VGA card and a "good" one. There are a few laggards at the bottom, partly because the Viper VLB is an ISA VGA+VLB Windows accelerator on a single card, and the write-up describes that a few of the other Diamond cards might have overly conservative memory settings.

I have my own UM8886AF board that is a little picky about PCI cards. A CL-GD543x or S3 Trio64V+ works fine, so I would recommend either of those, but a CL-GD5446 doesn't. The CL-GD5446 does work in my UM8886BF board, a later revision.

You will find those PCI cards a dime a dozen (not quite, but close) but the VLB cards a bit hard to find. There are lots of VLB CL-GD5424, 5426, and 5428 cards out there, and as the test results show they could still be middle of the pack depending on how the manufacturer designed the board. The VLB 542x pairs perfectly with a 486DX2-66 IMO, but it looks like you might be going for something a bit higher end.

Quake is too heavy for a 486, I don't know about some of those other games.

For the games you're looking at running, I would recommend Pentium systems, not 486s. Especially if you're looking to run things at 640x480.

Duke, Blood and Shadow Warrior may be okay at 320x200. Depends on your definition of "smoothly".

Quake will require a Pentium. From what I've seen of 486-100MHz benchmarks, you can expect ~10 FPS at 320x200.

That said for VLB cards, cards based on Tseng Labs ET4000 or Cirrus Logic 5428 should give decent performance.

For PCI, S3 Virge or Trio64 cards offer good performance and compatibility. Though you may want to see how compatible things may be with PCI cards, as I've read that 486-era PCI implementations aren't always great.

For the 486 any VLB card makes a huge difference. Under Doom that's up to 30fps vs. 11fps. (And Doom has a frame limit at 35fps). For Quake it doesn't matter because it's unplayable anyway 😀
Of course the same applies to ISA vs PCI. Under DOS the performance difference between various PCI card is not really relevant, but other factors might be important, like signal quality and compatibility with certain games

Performance is a non-issue for all but the very oldest VLB or PCI cards. Given a desire for SVGA resolutions, good VESA support is at least nice-to-have.

For PCI, a good-quality S3 868, 968, Trio or Virge card would be ideal - the chips will perform similarly and 1MB RAM is enough, but cheap S3 cards were notorious for terrible signal quality. Look for a good brand (Diamond, Miro, Elsa, Number Nine etc).

For VLB, it's probably best to just look wat what is available at an acceptable price and choosing that. If you can choose, here again S3 864, 868, 964, 968 or Trio would be best for compatibility (just avoid the old slow 805), but relatively ubiquitous Cirrus Logic cards are also fine in terms of compatibility. GD5434 would be best, but anything from GD5424 up would work fine for DOS gaming only.

Shponglefan wrote on 2023-08-09, 19:54:

For the games you're looking at running, I would recommend Pentium systems, not 486s. Especially if you're looking to run things […]
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For the games you're looking at running, I would recommend Pentium systems, not 486s. Especially if you're looking to run things at 640x480.

Duke, Blood and Shadow Warrior may be okay at 320x200. Depends on your definition of "smoothly".

Quake will require a Pentium. From what I've seen of 486-100MHz benchmarks, you can expect ~10 FPS at 320x200.

That said for VLB cards, cards based on Tseng Labs ET4000 or Cirrus Logic 5428 should give decent performance.

For PCI, S3 Virge or Trio64 cards offer good performance and compatibility. Though you may want to see how compatible things may be with PCI cards, as I've read that 486-era PCI implementations aren't always great.

Agreed. A 486 can still be plenty of fun though. OP, do these systems already have video cards and you're looking to upgrade? If you can identify them we can advise whether it's worth bothering to change them or just keep what you have.

jakethompson1 wrote on 2023-08-10, 00:55:

Agreed. A 486 can still be plenty of fun though. OP, do these systems already have video cards and you're looking to upgrade? If you can identify them we can advise whether it's worth bothering to change them or just keep what you have.

Unfortunately I don't have a VLB or PCI graphics card that fits in one of the 486.

I tested both systems with a Trident TVGA 9000C that I still have lying around. At that time, it already had a graphic error because the memory or chip had lost something. The errors there are e.g. incorrect lines, colors - especially with gray tones.

I do own 2 Diamond Viper 330 (Riva TNT), but since they are PCI 2.1, they don't run in the old system.

Shponglefan wrote on 2023-08-09, 19:54:

For the games you're looking at running, I would recommend Pentium systems, not 486s. Especially if you're looking to run things at 640x480.

I agree with you and I would do the same. If you haven't done it yet, the spoiler says why I asked about the 486.

I know that a Socket 5 / 7 system is better and I already have several, although from Chaintech, Soltek etc.
I also have an Asus P1, which only supports Intel P. Just hardly any things for a 486 PC.

Thanks for the previous answers. I can definitely do something with that.
Even if it is unfortunately true and VLB have become very expensive if you are still looking for one in good condition, especially the S3.
For the PCI I found some on Ebay and I'm going to buy one of the above.

Trident TGUI9440 VLB will also be good (in terms of compatibility and speed).

Ugh, yah, just checked fleabay the only thing anywhere near reasonable for VLB is a couple of GD5428 cards in Italy, shipping to North America high though. Electromyne doesn't seem to have anything.