https://bugs.winehq.org/show_bug.cgi?id=43049
--- Comment #2 from David K. hevanen@googlemail.com --- Yes, downgrading to 2.4 or 2.4-staging restores performance. 2.5 is the first bad release.
I have tried to run a regression test, but while setting up a LXC container for the 32-bit build, I ran into the problem described here: https://forum.winehq.org/viewtopic.php?f=8&t=28274 I haven't had time yet to look into it further.