[bno1]

Proton uses esync or fsync which (from what I've read) are on-par with ntsync. However, esync and fsync can't be merged into upstream wine because they can't properly emulate some quirks of NT sync objects, hence the ntsync driver.

[3v1n0]

NTSync still seems to outperform any userspace fsync implementation https://github.com/Frogging-Family/wine-tkg-git/issues/936#i...