Amithlon runs 68k exes, and your port is crazy fast on it
At low res (custom p96 256*192) I get roughly 1000 fps on my amithlon box
Weirdly up to 320fps it calculates and shows normal rates, but beyond that it just shows the closest multiple of 320. The rate at aforementioned res alternates between 960 and 1280fps.
Granted this is overkill and I run it at 2048*1536, but it was fun testing framerates at assorted resolutions
For those unaware, and interested simply type, "dnrate" during the game to have framerate shown in top left corner of the screen.