https://bugs.winehq.org/show_bug.cgi?id=44146
--- Comment #6 from Christian christian.frank@gmx.de --- (In reply to Józef Kucia from comment #5)
(In reply to Christian from comment #4)
(In reply to Józef Kucia from comment #3)
It's probably the same issue as in bug 42592.
Sadly i can not check that theory cause i don't own The Witcher 3.
You could try the patch attached to bug 42592 with vanilla Wine.
I did that and the fps have increased from 8 to 8 - 15 fps. It is still a slideshow but iirc, that hack didn't help much for nvidia cards for witcher 3 also. You even can see the issue in the menu, wine is not able to even deliver 60fps there.