DisplayLink ports use USB data connectivity and an integrated chip requiring driver installation to extend displays beyond a computer's native graphics processor limitations. In contrast, Alt Mode MST ports use Multi-Stream Transport over a USB-C cable to split a single native video signal directly from the computer's graphics processor, without requiring extra drivers.
How DisplayLink and Alt Mode MST Ports Differ
DisplayLink ports (marked HDMI 1 and 2) use an internal chip to manage display data over a standard USB 3.0 connection. This technique allows you to connect more external monitors than your computer’s internal graphics processor normally permits. Because this technology relies on data transmission rather than a direct video signal, you must install software drivers on your system. The latest drivers can be downloaded directly from https://plugable.com/pages/displaylink.
Alt Mode MST ports (marked HDMI 3 and 4) rely on DisplayPort Alt Mode over USB-C to route a native video signal directly out of your computer's graphics processor. Multi-Stream Transport (MST) splits this single native signal to drive two independent displays, allowing you to extend your desktop across two monitors (such as two 1080p displays). The final output resolution of these two monitors depends entirely on the DisplayPort version supported by your host computer, which requires a minimum of DisplayPort version 1.2.
Applicable To
- Host computers supporting USB-C DisplayPort 1.2 Alt Mode or higher with Multi-Stream Transport (MST)
- Dual-technology docking stations featuring both DisplayLink and Alt Mode MST video outputs, such as UD-3900C4
