I have an OpenGl application written in Qt (some details at the end of the post). In the Catalyst Control Center I have "Tear free desktop" enabled and "OpenGl vsync" set to always on.

This gives great results when running my application in windowed mode (on standard ubuntu and customized debian running openbox): no tearing at all. But when switching to fullscreen, tearing is visible. The settings in the control center do have some influence though when running fullscreen: there is less tearing, but it's not completely gone. When adding another widget in my application when it's fullscreen (e.g. a menubar), tearing is gone too, just like when running in windowed mode.

It seems like the fglrx driver behaves differently when the opengl context is fullscreen. Anyone know why and why I get tearing then?

Qt application info: A qgraphicsview with a qglwidget as viewport. The graphicsview visualizes a graphicsscene wich is for example showing a video, flash, qgraphicsitems etc at the same time.

Best regards,

Christophe