This article addresses a configuration requirement for daisy-chaining Dell U2415 monitors on Intel HD Graphics
Multi-Stream Transport (MST), also known as Daisy Chaining, is a new connection specification that allows multiple monitors to be connected in series with the video signal being passed from the computer to a monitor, and then from the first monitor on to the second monitor and so on. This differs from the traditional configuration of having a separate video cable run from the graphics adapter to each monitor in parallel. This simplifies the video wiring in most situations, but does have some specific configuration requirements to enable it.
Daisy chaining monitors is supported in the Display Port (DP) 1.2 specification, however, not all of the monitors to be included in the daisy chain configuration can be set to DP 1.2 due to how the Intel HD Graphics Driver functions. In order to enable Daisy chaining, the first monitor in the series (the monitor directly connected to the graphics card) must have DP 1.2 enabled in the monitor settings. The last monitor in the chain must have DP 1.2 disabled.
The reason for this is that the Intel HD Graphics driver requires a "terminator" signal in the chain to indicate the last monitor is the last monitor in the chain in which to extend (or duplicate) the desktop to. If there are three monitors in the daisy chain, then the first two monitors would have DP 1.2 enabled and the third would be disabled, and so on.
DP1.2 enables MST streaming. To the Intel HD driver, leaving it turned off behaves like a terminator in the chain . You may extend the desktop to the monitors with DP1.2 enabled, but can only clone any additional monitors beyond the terminated monitor.
To configure daisy chaining for 3 (or more) monitors:
Users can locate additional configuration details in the U2415 Monitor User Manual.
Article ID: SLN295251Last Date Modified: 07/23/2020 01:18 PM