My testing is far from scientific... I lowered down to a Pentium II 233 and it seems to always be at 100% with the games I've ran, but I just started using PCem a few days ago so I'd take my experiences with a grain of salt.

What would typically be the upper limit for a CPU like an i7-7700K?

How fast of an PCem CPU can you run on a modern desktop host CPU?

For example, I'm currently using PCem on an i7-7700K and successfully have used a Pentium II 233, but I tried a Pentium II 450 and things regularly slowed down.

Thanks!