Hi, if you have the previous GOTY version it will work but I'm not sure for previous other editions so try it. :)

Open GOG Galaxy> Owned Games/Installed> The Witcher 3> Manage installation> Configure> Beta channels change to Classic.

I recommend to uninstall the game completely from your computer first and then install it with version 1.32 (Classic) to avoid problems with the game. I understand that this may be an unnecessary guide but maybe someone will appreciate it. I'm posting this here because a lot of people are having trouble downloading patch 1.32 which is split into 10 parts. This seems like a simpler and better solution in my oponion.

Thanks so much, and bump.

Had drop to the 40ish in city, now at worst 90 fps ; huge perf gap...

IMO
And as my settings was restored : bless yourself and disable all post process effects except AO (sharpening being a matter of taste tbh and square) ; as for taa !
My pinch of salt, just try and guess what it's really about ;)

Take care, hf