Years ago I tried running my old C64 games on faster hardware was disappointed that many games from back then seemed to assume a particular CPU speed. For instance all the D&D boxed set games (like pool of radiance/curse of the azure bonds) would have characters move during combat based on the the speed of the computer. On a faster processor combat was over in a blink of an eye making the game unplayable.

I believe most of the software emulators slow down the clock speed so games are playable, but on actual faster hardware, there's prob a lot of non-playable games. I really don't know why this was the case :/