https://bugs.freedesktop.org/show_bug.cgi?id=29726
--- Comment #10 from Lucas lvella@gmail.com 2010-10-27 19:48:00 PDT --- (In reply to comment #9)
should be fixed on master DDX now.
Thank you so much for your commit. The vsync of the proprietary driver was broken in the second display in new Ubuntu, so I switched to the free driver, to find it much better than when I last saw it. No way I would go back to fglrx, but I still could not use the second display (my TV) the way I was used to (to watch movies, separated displays/screens, vsync on) because of this bug... I was using big desktop mode until now!
I just tested the driver with the fix, and vsync seemed to work in zaphod mode, in both screens. DISPLAY=:0.0 is my monitor with 1280x1024 at 60Hz and DISPLAY=:0.1 is my TV with 1920x1080, also at 60Hz. I played a movie with mplayer in both screens (gl backend, vsync on) and I could see no visible tear that was obvious when vsync was off. glxgears is also limited at 60 FPS, as it should be.
Now I am not sure how to test it without relying on my eye and a movie (I am satisfied with the result). My test may be unreliable, since I was not able to shut off vsync in mplayer in a way that I could see the tears I was used to see with vsync=off in fglrx. Env var vblank_mode=0 shows no artifacts, neither when running mplayer nor glxgears, although its FPS is not limited at 60 anymore.