I've never had any luck getting acceptable performance out of the Jane's Fighters Series (USNF, ATF, Fighters Anthology) with anything slower than a Pentium II 350.

I remember the DOS and Win 95 versions of ATF were basically slide shows in my Pentium 100 when I was a kid. And, now, with my newly finished Pentium MMX 233 Win 95 system, I'm getting no better than 15FPS at 640x480 with all the graphics options turned off. I would have thought a Pentium 233 MMX would be able to handle these games with relative ease. Are these games just that demanding of period correct systems?