https://bugs.winehq.org/show_bug.cgi?id=41394
--- Comment #1 from Matteo Bruni matteo.mystral@gmail.com --- That's weird indeed, Mesa on your GPU should support ARB_vertex_array_bgra so this patch should not make any difference on your setup. It's also pretty suspicious that it's not slow with apitrace.
I have downloaded the traces but I haven't looked at them yet. I also have a box with a similar GPU, I'll try to reproduce there (if I can manage to start that box again, at least...)
I guess you could also try to attach (or link to, if it's too big after compressing it) a +tid,ddraw,d3d,d3d_shader log with current Wine, maybe that will give us some clue.