SETBLASTER wrote:

# 3dbench2 gave 50fps, doom timedemo3 gave 3863 gametics ..4175 realtics, i guess that is normal for any AMD 100mhz 486PC
# IF i change the cpu to an AMD 133mhz, would that really make doom faster or how much mhz does it need to run at a higher framerate

So, you're getting about 33 FPS in Doom (provided you're running timedemo at the same settings you want to play the game). AFAIK, Doom is capped at 35 FPS, so any additional increase in benchmark results should be purely synthetic and not affect your actual gameplay.

Your score for Doom is on the lower side, recheck your settings.

A 100mhz cpu, especially AMD, is no speed king in Doom when gauged with a less nostalgic mindset - fire up DoomII Map22 and see if you like it.
Upgrading to a 133mhz cpu is definitely an improvement in parts due to its larger cache(given you're currently using an NV8T/B). But remember that the front side bus is one of the bottlenecks in Doom. So maybe try 3 x 40 before going for the 133 cpu.

The frame cap of 35 frames is not of much importance, partially including the timedemo, where latter represents an accumulated average... so peaks and valleys in performance may "cancel" each other out(a bit of hyperbole since the demo is mostly not made up of such extremes). There's not much use looking into a corner with 70fps to only dip below 20 when in the average scene.

Better use the -devparm parameter and play a very stressfull map(E4M2 for example). If it feels smooth enough there all other Doom performance related issues, besides user made absurdity, have been resolved.

The newer PCI cards you tried need a more recent PCI version which the old boards do not feature. Maybe try a Matrox or Tseng for the "fastest" speed but be aware that during ordinary playtime this peak performance won't buy you much if the system does not have plenty of steam from below(cpu+memory).

I've got a POD in that same motherboard.
Another 486 being built

I'll try and run benchmarks over the next few days and get back to you, but do remember its a perfectly ok motherboard but not the fastest.
I do have a 586 133 CPU as well but definitely won't be able to test that but as you can see from another of my 486's it'll be pretty much the same for doom.
Osbone 486 DX2 66 VL-Bus (My 1st PC ever)

From playing doom on this PC I can say your childhood is tricking you. A 486 does slightly struggle with doom, its been commented on here a few times as we have all been tricked.
Even the first Pentiums struggle i think (not sure never had one) I think the P100 is when Doom is silky smooth.

The IDE drivers enable bus mastering in early Win95 editions. They are redundant even in the later editions though.

This is the board with which I could finally break 100 fps in 3dbench. It was with the Am5x86 at 160MHz and fastest cache and memory settings. So it should be way more than 50 fps, I guess.

A Riva128 is a good start, though. It's a superb fast (2D) card for anything PCI only, great for DOS benchmarks and games and demos.

Oh, about BIOS settings. There must be a few options for PCI, they can nicely speed up VGA transfers.