On a late 2009 27" iMac (2.66 GHz i5), 10.9.3 Make the window full screen: 100.15 Full screen, no menu bar, dock: 71.27 While running a hangout session, and having about half a dozen other applications open. Is there buffering below this? Is there a difference when doing Display forceToScreen: rect; forceDisplayUpdate. Stephan