The UD-3900PDZ docking station can drive up to a maximum of three external displays using a combination of two different graphics technologies.

The docking station provides three labeled HDMI output ports, HDMI 1 is controlled directly by the computer's internal graphics controller, via USB Type-C DisplayPort Alternate Mode, or "Alt-Mode" for short. This enables the docking station to support HDMI version 1.4 — up to 4K 30Hz resolution, or lower resolutions like 1080P up to 60Hz refresh rate.

The HDMI 2 and HDMI 3 are controlled by DisplayLink USB Graphics technology — a combination of the DisplayLink software on the computer and DisplayLink DL-3900 chipset in the docking station. These ports can each support a single 1080P (maximum 1920x1200 resolution) display at up to 60Hz refresh rate, or using only one of these ports a single display up to 2560x1440 at up to 50Hz refresh rate.

DisplayLink requires installing the DisplayLink drivers for Windows or DisplayLink Manager for macOS. Both are available from our DisplayLink Driver Download Page. Detailed macOS installation and configuration instructions are available by clicking on the INFO button.

Note — Not all computers with USB Type-C ports support USB Type-C DisplayPort Alternate Mode to enable the HDMI 1 output on this docking station. Most Desktop computers, and older notebooks do not support this feature. If you would like to confirm compatibility please contact our support team via email at support@plugable.com and we will be happy to help!