Using Two Quadro Plex Units
To use more than four displays, you will need two Quadro Plex D2 units connected to an NVIDIA Dual Output HIC (DoHIC) card installed in your host system.
You also need to synchronize the displays across the Quadro Plex units. Connect the Quadro Plex units to each other using an RJ45 cable connected to the G-Sync connectors and then configure using the NVIDIA Control Panel Synchronize Displays page.
Typically, the north connector on the NVIDIA DoHIC card is connected to the Quadro Plex D2 unit 1, but you may need to experiment to determine the connection in your system.