http://bugs.winehq.org/show_bug.cgi?id=22478
--- Comment #19 from Roderick Colenbrander thunderbird2k@gmail.com 2010-04-30 10:48:07 --- Henri mentioned that he noticed this issue as well, so I have done some additional testing. During testing I used a patch similar the 'hack' attached to this thread to stabilize the fps. Further I made sure I ran using WINEDEBUG=+fps,-all. Between turning shadows on / off, I quit back to the main menu and started a new game (this is what I did before as well).
The framerate with the ClearSurface FBO patch: * 25-30fps with shadows=high (20% faster than before due to the stretch_rect_fbo patch)
The framerate withou the ClearSurface FBO patch: * 33-38fps with shadows=high
Except for the stretch_rect_fbo patch (which should be ignored for now) I do notice a big performance difference now. I have no idea what changed (except that this is a newer wine build but I doubt it matters). It should now be easier to locate the cause.