I have 2 new dell U2417H which I am trying to connect to my machine via daisy chained displayport. The computer I have it connected to is an HP 400 G3 SFF. I have confirmed that this computer supports MST via displayport. The current configuration of the connections are as follows:
CPU DP > First Monitor mDP input > First Monitor DP output > Second Monitor mDP input
Both monitors currently have displayport 1.2 enabled. I have done factory resets to both just to be sure.
Even though the display is mirrored on both monitors, windows does not detect more than one monitor attached. I am running a fresh install of windows 10 64 bit (I have also tried it on an identical machine fresh out of the box with the same result). I have updated the video drivers to the latest release. It is an onboard Intel HD 530 which supports multistream via displayport.
Is there any issues with using mDP ports instead of full sized form factor displayports? Currently The monitors only came with mDP to DP cables and the new cables are on the way, but are a couple of days away. From what I can tell, using mDP shouldn't be an issue because there is no difference other than they are different form factors.
Solved! Go to Solution.
The second in the chain should be set to MST/DP 1.2 Off. I would also swap them (current primary U2417H change to secondary U2417H) to see if the issue is the same. No, primary U2417H on mDP should work.
Not sure what else you can do but test them on another system with a dedicated video card that has DP or mDP and also testing with a DP to DP cable on that HP. Where did you find HP documentation that stated its onboard DP out port supports DP 1.2 daisychaining? That is not mentioned here or here ?
Tested with DP to DP, same result. It does mention it on the first PDF you linked. On page 22 it is listed under the 400 G3 SFF (small form factor), which is the model I have:
I do not think that the monitors are at fault here. Then the only other option is to test them on another computer. Preferably a computer with an added video card that has DP out or mDP out. Also contact HP support and ask if they successfully tested that system in a two monitor DP 1.2 daisychain.
I had this exact same issue with Dell U2717D monitors. The monitors were mirrored and showed up in the display manager as one single monitor. I played with enabling/disabling DP 1.2 on the second monitor to no effect. Finally I found out that there was another setting in monitor configuration that was simply called "MST". Evidently this is called "Multi-Stream Transport". Once I ENABLED MST (in addition to DP 1.2) on the first monitor, the displays un-mirrored themselves and Windows treated them as separate monitors. Enabling DP 1.2 and MST on the second monitor allowed me to daisy-chain a third monitor. They are all recognized as 3 separate monitors and can have independent resolution settings. At least for me, MST was the key. The MST setting on the U2717D is under DISPLAY -> MST. For me, at least, this fixed the issue of the displays mirroring while daisy-chained.
MST (Multi-Stream Transport) and DP 1.2 are the same thing.
Which is why I stated above, "The second in the chain should be set to MST/DP 1.2 Off.". As I showed in the picture, the U2417H manual calls them both out, "DP1.2 with MST option". As does your U2717D manual =
I'm going to try this same set-up, but with a laptop that has Radeon 540 graphics. The laptop has one USB type C and one HDMI - do you recommend using the type C port or the HDMI? I need to buy a new cable to connect to the mini display port on the first monitor. Thank you!
You cannot start with computer HDMI out to daisychain U2417H. It will have to be the laptop USB Type-C out port.
Computer USB Type-C out --> USB Type-C to DP cable --> #1 U2417H DP in (MST On)
#1 U2417H DP out --> U2417H DP to mDP cable --> #2 U2417H mDP in (MST Off)