http://bugs.winehq.org/show_bug.cgi?id=8295
--- Comment #28 from Henri Verbeet hverbeet@gmail.com 2012-02-02 15:06:28 CST --- (In reply to comment #27)
just a clarification regarding the performance - I've foud who kills it. It's the "Z Read" option at the very bottom of the graphic options (you have to set the Graphic detail to "Custom" in order to see it).
If that's depth readback, I think that makes sense. I wouldn't expect that to be terribly fast on Windows either though.