what's the average performance impact

[coffeel0RD]

with the current build

[Sonicadvance1]

The performance impact of FEX depends heavily on the application and what instructions it is executing in the moment.

If we're following averages of benchmark numbers then we can likely assume the impact of FEX emulation is somewhere in the range of 10-30% slower than native execution, but that doesn't quite tell the full story.

In /really/ good cases, we can actually emulate some code faster than native due to weird compiler choices.
In /really/ bad cases then the emulation can be a single digit percentages what the full native performance would be.

The biggest performance issue for FEX emulation is emulating the memory model of x86. Something that even the fastest ARM hardware on the planet can't avoid (ignoring Apple's TSO bit). So we have examples of games that run at 16FPS, but if we hack out emulating the memory model, it then runs at >140fps. This is just one example.

So we can make sweeping generalizations to get kind of an "average", but it needs longer discussions to really drill in to the nuance.

[coffeel0RD]

makes sense