IIRC, emulators are generally significantly slower than using the original console, so that probably has something to do with it.
Not exactly? It's not so much that they're slower as they tend to be more resource intensive. It usually starts off taking something like 2-3x the resources to run at the same speed, and can sometimes get less as the coding involved gets better. The difference being, naturally, that PCs can get a
lot more powerful than consoles tend to be able to manage. Add in simple stuff like frame skipping or general acceleration, and you get emulators that are significantly
faster than the original console, just chewing up more hardware power.
Just about anything below PS2 level, iirc, can generally manage to go faster than the original machine via emulator, if your hardware can keep up with it. PS2+ stuff, too, if your rig is really beefy.
Now, if your machine can't match the emulator's requirements... yeah, that can end up running slower than the original console, obviously. It's just not a necessary thing, heh.
And mostly ninja'd, but eh.