http://bugs.winehq.org/show_bug.cgi?id=27618
Roderick Colenbrander thunderbird2k@gmail.com changed:
What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED CC| |thunderbird2k@gmail.com Resolution| |INVALID
--- Comment #1 from Roderick Colenbrander thunderbird2k@gmail.com 2011-06-27 13:23:59 CDT --- The issue you are seeing is not a Wine problem. Bumblebee uses VirtualGL and the use of VirtualGL comes at an additional performance hit.
The way things work when you use VirtualGL is that all 3D content is rendered on the Nvidia GPU. In order to show the images on your screen, every 3D frame has to copied back to system memory and copied back to video memory on your Intel card. This is quite slow and stress the PCI-E bus quite a bit (especially on laptops where you typically have much less bandwidth). It directly slows down the game as well because this is all happening during the 'glXSwapBuffers' call the game makes.
On Windows the Nvidia drivers use similar VirtualGL-like tricks to render on the Intel GPU, but there are a lot more optimizations are in place (and there is likely more direct interaction with the Intel driver).
At least this issue is definitely not a Wine bug.