How can emulators effectively speed up their gameplay to 5-10x speed?

Question

I understand that emulators have to convert “console-language” to “emulator language” which causes stutters and otherwise poor performance.

But how can that same emulator play the game at 5-10x the speed using speed up features without sacrificing gameplay, loading screens, or resolution?

I just played through an emulated gamecube version of Twilight Princess with a 4K texture pack, which had its fair share of stutters. But I could also hold the speed-up button during loading zones and while saving my file and the game would handle it just fine.

If it requires extra processing power to emulate, how come emulators can speed the game up to such high speeds?

In: 15

Answer 1

Emulators use tricks when running at higher speeds.

Not all instructions in the console take the same amount of resources to emulate so one way to speed it up is to just ignore certain types of graphics or audio commands. If I’m at 4x speed I only need to actually draw every fourth frame to the screen for example. (Though there are some games where this does not apply because they’re doing atypical things with the graphics data for example).

So something like saving where almost all the CPU time is spent writing a file and not on hard to emulate things you can speed up to take advantage of better hardware on your computer compared to the original hardware.