Thanks for the advice, I didn't know about write combining.
After some research found a tool called setk6 which enables the feature and was able to set it up, but to be honest I didn't see any noticeable increase in performance on "high definition" DOS games, plus the tool does not work with EMM386 which I need for a lot of my games so I ended up disabling it in pure DOS (I am using the windows version, though, just to see if I can get any improvement).
As for MBF, with the -noasm flag there was no noticeable difference, the -lowdet flag however improved the performance (and worsened the graphics), but there is still noticeable slowdown when hugging walls.
I even tried with the onboard video card to see if it is a video related issue (ATI Rage PRO), but the issue persists. This is sad because MBF is so much faster than Doom Legacy on 640x400...
My system specs in case you have interest in investigating it someday:
K6-2 450mhz
256mb RAM PC133
V72MA Motherboard
SoundBlaster AWE 64 Gold ISA
Diamond Stealth 3D 2000(Virge S3) 2mb
Voodoo2 8mb
Thanks a lot for the support.
LO-RES, HI-FUN
My DOS/ Win98 PC specs
EP-7KXA Motherboard
Athlon Thunderbird 750mhz
256Mb PC100 RAM
Geforce 4 MX440 64MB AGP (128 bit)
Sound Blaster AWE 64 CT4500 (ISA)
32GB HDD