Multiples screens, one window and fullscreen

Hi all,

I know It has been a famous topic here, but I’m still not sure about a correct answer so, I put the topic on again!

I’m doing an application using two screens in full screen mode ( with mac osx ) using the extended desktop.

I understood that because of a desynchronisation of the screens frequencies, the framerate of the application can’t go more than 30 fps.

I’ve been also testing options like ofxCocoa and verticalsync, but the result is quite the same in my case ( more stable but a weird + 40% ram usage and 30 fps too ).

30 fps is fine though, but when I’m displaying video, ( using ofxQTKit ), the fps drops in a regular way, to 25fps, for 2 seconds, and them go normal, and so on…
Using ofVideoPlayer, the framerate just go very unstable.

Results can be better depending the video compression though, but the drops stays here, and only in full screen.

Someone had this issue before ?
What could be the best way to deal with one window and two screens ?
Is there some kind of possible hack / workaround ?

I’ve read somewhere about having various window and an openGL shared context but this seems far out my knowledge !

I would be very happy to know more about your advices

Many thanks,