I've tested Duke Nukem 3d and BLOOD and in both of these games, I'm catching occasional hiccups when smth new happens on screen. So I've got two machines and my mind is blowing already.

Toshiba Satellite Pro 430 CDT (P1-120mhz, 16mb ram)
Toshiba Satellite 2805-S402 (P3-850mhz, 256mb ram)

I've tried running these games in pure dos. I've tried running them with sound disabled. In 430CDT I even tried switching from HDD to Compact Flash "SSD". I've also tried enabling and disabling smartdrv.

Still, I'm getting this:
https://www.youtube.com/watch?v=fZiTYhhNR_c (It's captured in slow-mo to highlight the hiccups, in real gameplay it really fast)
Another sample, from Duke: https://youtu.be/ETNEU827yfY

Guys, I don't know what to do. No idea...

I've tried some other games: Descent, DOOM, Quake. They don't suffer from these hiccups. But on 2805 I've tried Thief II and it also stutters when the game needs to load smth from HDD.

The most strange thing is that I've got Siemens Nixdorf Scenic 710 (P1-233mhz, 32mb ram and CF "SSD") and I've no stutters and hiccups. Nothing. Fluent gameplay.