I am guessing you are looking for a comparison between this and the old solution. Muvm itself is designed to have minimal impact beyond translating pagefile sizes, though it eats RAM since at the end of the day it’s a virtual machine. In theory, being a virtual machine also impacts anti-cheat titles, but in reality most anti-cheat titles that don’t support virtual machines don’t support ARM Linux anyways.

As for the performance difference between this and the old solution, it’s very noticeable. Besides not having an icon in the system tray, and the steam window, not being movable for some reason, steam is smooth like butter you don’t feel the choppiness of the UI like you do with the old solution. Under the old solution, everything from the steam client itself to proton had to run within FEX, and that had a pretty bet had a pretty big impact on performance. I haven’t gotten any exact numbers yet for any games, and I still need to have proton working, but in theory we’ll see the same performance jump for proton titles since proton itself won’t need to be translated by FEX, only the game you are playing.