Daisy Chaining explained

Question

DP = DisplayPortmDP  = Mini-DisplayPortMST = Multi-Stream TransportDP 1.2 = Turns on daisy chainingDaisy Chain = Connecting a second monitor to the first monitor via the usage of the first monitors DP out port and the second monitors DP in port or mDP in port. The first monitor must support enabling or turning on DP 1.2/MST in its OSD (On Screen Display) Menu and must have the DP out port. How to Daisy Chain Multiple Monitors Using DisplayPort Multi-Stream Transport (MST) To use two monitors in a DP 1.2/MST Daisy Chain, the source PC video out port MUST be either =TB3/USB-C outDP outmDP outAll slaved monitors must use either the DP in port or the mDP in portThe source PC video out port (even with active converters) can NEVER be =HDMIDVIVGAAny usage of HDMI/DVI/VGA port, cable, or adapter for or on the second monitor will break the DP 1.2/MST Daisy Chain.It is not possible to daisy chain three monitors off of a laptop that uses the Intel integrated GPU or Intel Hybrid GPU. The maximum will be three total displays = laptop screen + two external monitorsLatitude 7480 USB Type-C out port --> USB Type-C to DP cable --> #1 U2417H DP in port (MST On)#1 U2417H DP out port --> U2417H DP to mDP cable --> #2 U2417H mDP in port (MST Off) U2414H DP 1.2/MST Daisy Chain* PC mDP out port --> U2414H mDP to DP cable --> #1 U2414H DP in port (left) (Menu- Display- DP 1.2 Enabled)* #1 U2414H DP out port (right) --> U2414H DP to mDP cable --> #2 U2414H mDP in port (center) (Menu- Display- DP 1.2 Disabled)-or-* PC DP out port --> U2414H DP to mDP cable --> #1 U2414H mDP in port (center) (Menu- Display- DP 1.2 Enabled)* #1 U2414H DP out port (right) --> U2414H DP to mDP cable --> #2 U2414H mDP in port (center) (Menu- Display- DP 1.2 Disabled)-or-PC Thunderbolt 3/USB Type-C out port --> TB4/3/USB-C to DP 1.4 cable --> #1 U2414H DP in port (left) (Menu- Display- DP 1.2 Enabled)#1 U2414H DP out port (right) --> U2414H DP to mDP cable --> #2 U2414H mDP in port (center) (Menu- Display- DP 1.2 Disabled)U2717D DP 1.2/MST Daisy ChainPC mDP out port --> U2717D mDP to DP cable --> #1 U2717D DP in port (left) (Menu- Display- MST On)#1 U2717D DP out port (right) --> U2717D DP to mDP cable --> #2 U2717D mDP in port (center) (Menu- Display- MST Off)-or-PC DP out port --> U2717D DP to mDP cable --> #1 U2717D mDP in port (center) (Menu- Display- MST On)#1 U2717D DP out port (right) --> U2717D DP to mDP cable --> #2 U2717D mDP in port (center) (Menu- Display- MST Off)-or-PC Thunderbolt 3/USB Type-C out port --> TB3/USB-C to DP cable --> #1 U2717D DP in port (left) (Menu- Display- MST On)#1 U2717D DP out port (right) --> U2717D DP to mDP cable --> #2 U2717D mDP in port (center) (Menu- Display- MST Off)I turned DP 1.2/MST On and get a black screen?This means that either your video card or the driver is not DP 1.2/MST compliant.* Press the monitor Input Source select button* Highlight either DP or mDP* Hold the green check down for 8 seconds* Disable DisplayPort 1.2

jphughan · Answer

Very nice! I will simply add that a triple display daisy chain from an Intel GPU system is possible as long as the built-in display is set to disabled -- which is only possible on Windows. On Linux, the built-in display can't be completely disabled, so it always counts toward the GPU's maximum display count. (And the total bandwidth requirements of all 3 displays must also be within the total display bandwidth available on the chain, but that's true of any daisy chain setup.)

In addition, the use of an active DisplayPort to HDMI adapter, like this one, can at least sometimes be used to drive the last display in the daisy chain. For example:

PC's USB-C out > USB-C to USB-C cable > Display #1 USB-C input > Display #1 DP MST output > DP to HDMI active adapter > HDMI cable > Display #2 HDMI input

This has been confirmed to work in at least one case I've seen here, but I can't know for sure whether it would be universal. But the reason it at least CAN work is because in this case, from the PC's perspective and the perspective of all displays in the chain except the last one, the entire signal chain is still using native DisplayPort signaling. The only portion that's native HDMI is the signal between the active adapter and the last display, which is fine because the last display doesn't need to "know" that it's at the end of a chain. But again it only works on the last display because a display that is receiving an HDMI signal cannot continue a daisy chain "downstream".

Brad L (retired) · Answer

Helpful Video:

Monitors

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