http://bugs.winehq.org/show_bug.cgi?id=27298
--- Comment #24 from Jonathan Strander mblackwell1024@gmail.com 2012-10-26 19:14:55 CDT --- Seems like Metacity does some compositing (after talking with some folks). Killing the WM as a quick test produces the same performance as a new Xserver. So it looks like I was mistaken (apologies!).
Also I did longer benchmarks and it seems the highest average fps I can produce (standing still looking at a single scene) is around 33fps (with GLTO). This is about 75% of Windows performance*. However there are still massive frame drops in certain scenes (which drop the framerate down to about 15-17fps, 12-14fps with Gnome Shell). These are not short-term hitches as they never resolve to a higher framerate.
I'd still like it if someone could point me in the direction of figuring out what TW2 is spending the most time on in Wine and getting things cleared up.
*The caveat here is that I'm actually running with slightly lower settings than my GPU should be able to handle on Windows. But this is probably expected anyway since my CPU is a Q9550 rather than an i7 as listed here:
http://www.geforce.com/Optimize/optimal-game-settings/Witcher-2-The-Assassin...