I would think those that run 66mhz pci if available in VLB would be the most likely.
(There was a thread here about the ultimate 5x86 that listed a few, too bad voodoo 3 never was vlb)

Also on my boards there is a wait state but the frequency isn’t changed

Weren't most VLB systems based on a 486, which topped out at a 50 MHz bus speed? All of the DX2 and DX4 chips have 25 MHz and 33 MHz system buses, which most VLB cards are perfectly happy with from my memory.

MadMac_5 wrote on 2023-06-29, 21:37:

Weren't most VLB systems based on a 486, which topped out at a 50 MHz bus speed? All of the DX2 and DX4 chips have 25 MHz and 33 MHz system buses, which most VLB cards are perfectly happy with from my memory.

The M919 has jumper options for 60 and 66 MHz. I suspect other VIP boards do as well, but I haven't made a list.

From my experience most decent VLB graphics cards will handle 60/66MHz, but only if the motherboard supports them to the required level.
What i mean here is that the motherboards are the bigger factor by far.
Unfortunately this area is not studied well enough to draw definitive conclusions.

From what i saw:
The most predictable/stable card is Diamond Stealth 64 DRAM, but keep in mind that i deliberately ignored the Vision series as its predecessors. There is a good chance some of them exhibit similar qualities. Also, there are newly made Trui64+ cards that should also handle 60/66 (tbd soon).
Cards based on CL GD-5434 and 5428/9, Western Digital WD90C33-ZZ, Trident TGUI9440* are also great options.
Ark1000VL is more picky.
Then is everything else.

About motherboards:
There is a vast array of classic 486 ISA/VLB motherboards.
SiS 82C471 based ones are the better place.
Few specific models are great at 60/66.
Some UM8881 based models such as M919 are good options as well.
(Keep in mind that M919 does not handle 3x66)
Some late VIA based models are pretty much hustle free, but a bit slower than the rest.

There is a large array of classic ISA/VLB 486 motherboards.
I don't think it is possible to inspect all of them, unless big investment of time and money is involved.
So there is a good chance there are hidden gems out there that wait to be discovered.

So in short - If you want 60/66MHz VLB system - make sure you have the right mobo.
Good chance your decent graphics card of choice will be happy with that.

So far, I've only tried the Trio64 and Trio64V+ on the m919 at 180 MHz. Trio64 worked, but the Trio64V+ did not. I'll run through my VLB cards, but I don't have all that many cards. From your response, sounds like the ARK1000VL probably wont work. Perhaps the VLB cards which aren't the fastest will work.

Which specific VLB graphics card and motherboard combinations have you tried at 60/66 MHz and confirmed they either work, or do not?

The only data point I have is that I once tried a VLB Trident 9440 at 60MHz in an M912 (with Cyrix 5x86-120), and the computer booted but Windows 3.1 had frequent crashes which seemed related to the video driver. However I don't remember if any waitstates were enabled via the video card or motherboard jumpers.

I ran a few quick tests with my M919 v3.4 at 60 MHz x 3.

Working
Spea S3 968 (tested NT4)
Diamond S3 Trio64 (tested NT4)
ARK 1000VL (needs 1 ws jumper set, tested DOS only)

Not working
GD5428
Trident 9440
Mach64
Trio64V+

Unfortunately, needing to set the 1 ws jumper on the ARK 1000VL card slows it down some. Is ARK 1000VL normally faster than any PCI graphics card on a 486? Some Quake numbers:

Matrox G200 = 21.2 fps
ARK 1000VL = 21.0
Trio64 = 20.9
S3 968 = 20.6

The G200 is running at 30 MHz PCI, while the VESA local bus cards are at 60 MHz.

I have had GD5428s and GD5429s running on 60Mhz, but they are hugely implementation dependent. If the board won't do 40Mhz at 0ws, it's unlikely to hit 60. Really we need to know the exact model/manufacturer of boards that do 60+, I wish I could oblige with the two I know for sure did, but they got left behind in the 1990s, so not until I retest currently held ones will I know if I've got one capable. (One of which might have been one of the originals, but unsure) ... Some of them get really hot though, they will work for half hour or so but then heatsoak and get scrambled graphics in Win 3.11 so they need a heatsink on them.