Latest driver MGA Powerdesk 4.31.041. has some glitches in D3D on DungeonKeeperD3D as I reported earlier (Flickering lights, Flickering Dungeon Heart), but also has glitches on some! Textures in Jedi-Knight.
Though I have JediKnight 1.0 perhaps that's the issue. But I also checked the Texture-size to be "8" instead of "1" as recommended for that card. But it's still broken...so I have to check the drivers and the games again.

In tearms of the cable you mentioned. There is a special cable that has nearly no negative effect on the image-quality if used as loop-cable on early 3D addon-cards. The quality is brilliant. I only use those for every setup with a voodoo1/2 addon card. The quality is much better than the standard-ones and even much better as the s-video-solutions some (miro) cards had. There is an article about that...I have to check my archive.org links for that if someone is interested.

For my old tests I remember the cable that came with the Voodoo2 I have was quite thick and seems like shielded enough but I suppose that the PCB quality of the brand/model is a factor, than there's that cable, than there's the monitor cable itself, the amount of other cables around the monitor cable and finally the monitor quality itself to elaborate/maintain the signal quality internally.
For example I remember quite a difference from first Voodoo cards and the Voodoo II improved the signal quality and there were cases like the DVD decoders that were really difficult to solve. Various PCB revisions of the same cards (and maybe also some component choices/lifetime) make every Dxr3 DVD decoders to have a different and "unique" not good signal quality and a strong VGA quality output (Matrox) and a CRT were able to mitigate that while LCD cannot easily or often not designed to imho. Also the cable that came with Dxr3 was really thin, imho cheap and with a specific connector. From the analog game console experience with the RGB cables, I think many problems would be solved with a double-shielded cable for each wire from the start to end of the connection but those wires costs a lot and imho most cables have most probably not that solution cause they'd cost much much more.

Here is how I activate write-combining. Very simple, but if it's 100% correct...I don't know, but it seems to work.
Beside that JediKnight-DF2 and JediKnight MOS list MatroxMystique as official supported.
I have Version 1.0 of both (DF2/MOS) and the latest driver that does not break direct-draw accerlation has some texture-glitches on both supported games.
Interestingly enough the readme on MOS (the later game) mentions that the supported and tested driver is the old one 3700 that is good on D3D too but breaks hardwarescolling on direct-draw.
In Motoracer I use the "fully d3d" which is 3.20/3.22. the only glitch in d3d with the lasted driver is the black smoke instead of white.

There is a lot of testing to do!

dr.zeissler wrote on 2022-01-06, 19:24:

Here is how I activate write-combining. Very simple, but if it's 100% correct...I don't know, but it seems to work.
...

I can't tell from the output if you've got it properly configured or not. The last screenie does show two PCI framebuffer ranges (these would have to be checked against what is shown for the Mystique in Device Manager). Also a bit lower it says that write combining for LFB (= linear framebuffer?) is off. Maybe you have it set up just how it's supposed to be, but for me it would be easier to read if you posted a screenshot of CTU after Windows had started, because that's what I used.

You would also have to have some kind of benchmark tool to be able to tell if the tweak makes a difference or not. I used 3DMark2K, but given your card, you may have to choose something older.

I'll upload the texture glitches the mystique makes on DungeonKeeper1 and JediKnight. It's obvious a driver issue.
In earlier driver versions it's OK but the later drivers are broken on some textures in some games.
Beside that I must have to use the latest driver because scrolling is broken on the earlier ones. Perhaps a chipset issue?

The "broken hardware-scrolling" on early win9x drivers for matrox mystique is simply the deactivated vsync.
How can I enable vsync on matrox mystique and early win9x-drivers? (mostly for direct-draw).

This will be too fast on early drivers like 370 https://www.pouet.net/prod.php?which=8410
It only works on the latest win95 drivers from 1999.

Oh man that's some nostalgia right there , I had a matrox mystique in the home pc when I was a kid , we had some sort of pentium 2 or 3 rig cant remember the details , It came bundled with a buncha matrox specific games. I do remember running some other non matrox stuff like gta 1 and croc 2.

Still have the cds , I think there's a mechwarrior 2 one lying around somewhere as well. They're all scratched to hell and back though xD.

Btw I think that matrox jester is hella creepy.

Can someone confirm my experiences?

PCI Matrox-Mystique Win95b/DX5/6 ALi-Chipset ACER 2100 Board:

***TEXTURE-ISSUES***
DungeonKeeper1 D3D
- works only with the 1997 driver without issues (370)
- later versions have : flickering lights, flickering background, flickering dungeonheart, unreadable text ingame. (depends on the driver you use which glitches you get)

JediKnight DF2
- works only with the 1997 driver without issues (370)
- later versions have: texture-glitches while moving towards walls/textures. only some textures are effected but it obvious. ***FIXED*** value "32" in min Texture-Sitze Option!

FinalReality
- works with the latest driver, the earlier 370 has massive glitches on textures and objects.

***V-SYNC-ISSUES***
GianaWorlds, Horizon-Demo, Lomax, DX-Boulder and all other 2D DirectDraw Accelerated stuff
- works only with the latest driver from 1999 (MGA Powerdesk 4.31.041) because V-Sync is working in the driver !
- all ! earlier drivers do not have v-sync active for DirectDraw Acceleration and I can't find a switch or software to turn this on. So these software will either wobble/stutter or will be very fast (depending on your cpu)

Dos-Software in Win95:
- works with every driver, also v-sync is working on dos-demos/games even with the early drivers where vsync is broken on direct-draw

2D-Accelerated stuff that has v-sync option:
- interestingly this works fine, even on the early driver (370) Examples: Pitfall-TheMayianAdventure (v-sync to monitor fullscreen), Earthworm-Jim, etc.

As you can see, there is no real sweet-spot here until I find out:
- How I can activate V-sync for direct-draw on the 370 driver (so forget about finalreality)
- How I can eleminate those texture-glitches on Dungeon-Keeper1 and JediKnight on the latest drivers.

Perhaps someone can help me out?
Thx Doc

I upgraded to DX6.1 on that machine in order to test GTA2...man this runs beautiful in D3D on that mystique but it crashes with a hard system freeze after playing for some minutes. The crash is so hard that it destroys the Win95 Registry so hard that Win95 has to be reinstalled...I double checked this and the failure was reproducible. Too bad...

Seems to be an issue with the machine...could be everything...overheating cards, power-supply...unstable RAM...leaking caps etc. this will be a hard one.
I have another machine to test this...we will see...

I found a sulution for the StarWars Jedi Knight Games. There is an Option "min texture-size" or something like that.
With other cards like PVR you have to put a very small number in that e.g. 1-3... the mystique requires "32" as value to not produce texture-glitches.
So there is only DungeonKeeper1 to be fixed with the latest (and best!) mystique driver. Hopefully I find a solution for that too...

EDIT:
If I don't install the matrox driver on win95, my matrox mystique get's native drivers from DX5.2! Interestingly these work with 2D and 3D (tested with POD-D3D), BUT
with these drivers I get an note on starting Dkeeper1-D3D that says that the card lakes a feauture that is required for DKeeper (alpha-texture-blenden or something like that).
The matrox driver seems to fix/override this but in terms of functionality there are still lot's of glitches in lightning/textures on mystique, even if the readme says mystique is supported by DKeeper1-D3D.

Strange!

Doc

DoungeonKepper1 D3D could be fixed if I make a complete fresh Install of the game, patch it and upgrade with D3D. Not everything is fine with the latest MGA-driver. Problem fixed 😀
But I now have another strange problem that I could not fix in several hours. I had to change the Solo1 against a SB128pci. The SB128pci does not work in Dos and within Dos in Win9x.
The card initiales completly but no game/demo runs with sound, the card is never found, no sb-detection at all.

Another thing to fix is the 85hz mode for some early msi-games. My tft won't run on 85hz...but I never found a fix for that.

dr.zeissler wrote on 2022-12-07, 19:47:

I upgraded to DX6.1 on that machine in order to test GTA2...man this runs beautiful in D3D on that mystique but it crashes with a hard system freeze after playing for some minutes. The crash is so hard that it destroys the Win95 Registry so hard that Win95 has to be reinstalled...I double checked this and the failure was reproducible. Too bad...

That is why I install scanreg on Windows 95.

No problem for me "retter" reinstalls the latest backup in less then two minutes.