List of which ports can be used for Collage mode.
What digital or analog ports can I use to enable Collage Display?
To enable Collage Display, you can connect VGA, DisplayPort*, DVI, HDMI, and embedded DisplayPort in any combination of two or three displays.
To enable Collage Display on four displays, you can connect two external DisplayPort splitters with four DisplayPort panels, with a native resolution up to 1920 x 1200.