When the image is cut horizontally during playback and displaced this is called Tearing. This artefact is caused by incorrect syncing of graphics card and monitor or projector. For single display application this problem can be solved by selecting the appropriate playback mode.
For multidisplay mode with one computer playback must be synced with the connected individual displays. Basically, this is possible with the software-based playback mode Multihead (manual sync adjustment). See Adjusting the graphics output synchronization.
Unfortunately, manual and software-based syncing tends to be instable and, even with a successful setup, move from bottom to top or the other way round making readjustments necessary. In principle, this happens with all consumer/gamer graphics cards. A solution can be hardware-based syncing offered by some graphics cards, e.g. Nvidia Quadro M4000, M5000 and M6000.
Nvidia Quadro graphics cards we have introduced the special playback mode Multihead (Nvidia Quadro Sync). In this mode the graphics cards automatically syncs playback of the graphics outputs. A necessary precondition, however, is that all graphics card outputs use the same EDID (Extended Display Identification Data), i.e. with identical timing. See also Synchronization of the graphics output for Nvidia Quadro graphics cards.