It is not 100% clear (to me) where you are playing the games having issues, DOS 6.22 or Windows 98 SE?
What sound card are you using? Do you notice the lag while music is playing? Or sound effects? Pinball is a good game to test this theory.
Have you tried to install the same games into Windows 98SE (if the problems were DOS 6.22) and play them dropping into 98SE DOS mode?
Or are you playing in a 98SE Command Prompt while Windows is running?
What happens if you drop the RAM to 256MB (or less)?
Which Voodoo3 Driver do you have installed (if playing in 98SE)?
Which DirectX version is installed (if playing in 98SE)?
Which VIA 4-in-1 package do you have installed (if playing in 98SE)?
If playing in DOS, are you loading some kind of VBE (not necessary for the Voodoo3)?

Sorry if I wasn't clear enough this topic is for pure MSDOS 6.22 only.
I just mentioned that in Win98 everything works fine.

For Msdos it doesn't make any difference if you have 512mb ram or 4gb ram, no difference at all.

Try running doom2 with dos/32a extender instead of the supplied dos4gw.

I played a lot of these games (DOOM, Vikings, Bio Menace for sure) in pure DOS (Win98 DOS 7.x though) on my K6-II rig and don't recall any major issues. Definitely not lockups. Maybe some scrollers have choppy scrolling at times (don't remember which), but for sure nothing deal-breaking or I would have remembered.

It may be a compatibility problem between the card and the other system components. a K6 rig is different from a P3 one (even though mine is also a VIA chipset).

Which monitor do you use? 70Hz CRT or 60Hz LCD?

Monitor is some HP LCD it's native resolution is 1920x1080 and 60Hz it has VGA/DVI. Actually I doubt the issue is the monitor but will try some other later.

It's like there is a weird screen lagging in the mentioned games.

I have retested them with an S3virge 1MB PCI card and come to the same conclusion that doesn't help much so the problem is somewhere else. I have also tried without sound drivers loaded.

Tried Msdos6.22 and the latest FreeDOS.

Gopher666 wrote on 2022-03-20, 11:56:

For Msdos it doesn't make any difference if you have 512mb ram or 4gb ram, no difference at all.

Some DOS games tend to crash if the computer has a large amount of RAM. Descent and Descent II comes to mind if there is more than 64MB RAM.

Gopher666 wrote on 2022-06-23, 22:06:

Monitor is some HP LCD it's native resolution is 1920x1080 and 60Hz it has VGA/DVI.

VGA 320x200 screen mode usually runs at 70 Hz and that monitor is forcing 60 Hz, causing uneven frames.

Edit: Are you using VGA or DVI port from the monitor? Just to make sure.