I'm not sure how to disable vsync in DOS in this machine. I highly doubt there are any utilities to do so. As for Descent 1, was there even an FPS counter for it?
As for CPU speed you raise a good point, I did not artificially modify or slow down the CPU or anything. Everything was stock yet the games I have tried like Descent seems to run at the right speed although I would recall it being quite speed sensitive. I wonder if the Lenovo has capped the CPU's real and protected mode performance in some way by default.
It would require more investigation time and effort. I actually intended for this experiment to be done for fun and was not meant to be a comprehensive test and review.