I am trying to play a game, Ashes to Ashes that uses INT1A instructions for CPU speed. On modern systems since privileged instructions are not allowed, DxWnd converts them to GetTickCount calls.

I tried running the game on the same CPU, on both WinME and Win11. The game ran very fast at 1040FPS average on Win11.

Here's my question: Why did games run at correct speed back then? Was it because the games then rendered low FPS to get correct speed? Or the games rendered as much frames as it could but 1 frame has "lesser changes" because of slow CPU speed?

This question also applies to DOS, the games can be slowed down with a slower clock, but does it imply less frames get rendered?