http://bugs.winehq.org/show_bug.cgi?id=9768
--- Comment #2 from Stefan Dösinger stefandoesinger@gmx.at 2007-09-26 05:14:40 --- I am tempted to blame the driver for this. 1500 3Dmarks loss is a very massive loss, I don't think plainly enabling the stencil test can cause this. It may force the driver to fall back to software rendering for some reason. The Geforce 8 drivers are known to have big performance issues on Linux. Do you have a geforce 7 or geforce 6 to test with?
What is interesting too however, is that the stencil test was incorrectly disabled before, and the app still worked. This may be an attacking point for a workaround of the driver bug(if it is one).