https://bugs.winehq.org/show_bug.cgi?id=35418
--- Comment #23 from Alexandre Julliard julliard@winehq.org --- (In reply to Sebastian from comment #21)
On the other hand, why use DIB buffering at all for GDI applications? In both XP and WINE, nearly every metric in this benchmark is significantly faster with direct rendering. Windows 7 is mediocre and can't reach XP or WINE performance - I guess Win7 forces DIB buffering regardless of the application setting.
It may be faster, but it's not always correct. There are many GDI operations that cannot be implemented correctly in X11. Switching to client-side rendering has fixed a lot of graphical glitches, and also improved performance noticeably in many cases.
Note that X11 rendering isn't always faster. The same benchmark on my machine (GeForce 320M, nouveau driver) shows X11 being slower by a factor of 2.
I wonder if it would be possible to force a buffer flush at regular intervals, > maybe at 30Hz, even when DIB buffering is enabled?
We will probably want something like that eventually, but it's not trivial to do in the existing architecture.