Hi Right, did the test and all was fine (no tearing on either screen) tried them as asked, around 60fps on both. Then I made put both full screen and still okay (60fps). I then made another copy. Had laptop screen, thunderbolt display and HDMI monitor all displaying fine, then all full screen and still all okay (60fps). Then I opened ME, loaded the comps in to both decks, and all the QC were fine (60fps), but the ME output was tearing (only on the output window, not the decks) and the fps on the output window was around 30fps, again with all three comps displaying 60fps full screen!) I hope I have described this okay for you!! ??