"I just ran Daggerfall with 20k cycles and while it still ran, it would have given me a headache in a short period of time due to screen-tearing and such."
Correction, here. I haven't played Daggerfall in awhile and the last time I did was with dosbox .65, in which dynamic core would cause all sorts of graphical abnormalities in Daggerfall. It runs fine at 30K on a 3.2GHz system in version .72 with dynamic core set. ~24K was about as high as you could get it on normal core on the older versions (and probably still is).
In any case, 20K cycles on a dynamic core in recent versions (And 24K on normal core, I guess) was fine for everywhere except in buildings, where I did experience notable slowdown for some reason.
But yeah, the same basic principle still applies. 30K is great on the 3.2GHz system because it's faster. On the slower systems, 30K cycles is more than they can handle, I guess, so you actually see a performance increase with fewer cycles.
However you have to keep in mind that Daggerfall wasn't really coded that efficiently anyway.