Thank you for contacting Intel Communities.
You can check the following document for the max supported amount of displays and the resolutions:
Intel® NUC Board NUC5i5MYBE Technical Product Specification > Page 24
I hope this information helps.
Please don't hesitate in replying to this post if you need further assistance.
Thanks for the spec. Though I did check the file you refer to and that's precisely why I asked the question.
The spec only says dual DP 1.2 at 4k@60hz should work without providing any clue why jayburd failed in running his two UP3214Q.
Without clarification whether it's simply because of the MST issue or if there is any inherent reason why this would not work it's impossible to figure out if this is going to work with two P2415Q.
Sure I can make the purchase then try but I might well end up with a 4k monitor hanging around doing nothing...
I couldn't tell why the configuration you are referring to didn't work.
I found this information from Dell that you may find useful.
The DP cable that goes from the Intel® NUC to the 1st monitor must be 1.2 high speed compliant.
With 2 monitors connected by MST you can get up to 2560x1600 at 60 Hz.
You can also use the 2nd DP to connect a monitor and set its resolution to 3840x 2160 @60Hz.
Well, this is irrelevant - MST does not necessarily mean daisy chaining!
If you actually spent a couple of minutes reading the previous question you will be convinced jayburd did NOT daisy chain his two monitors.
Nor is this what I'm talking about.
What I'm talking about is connecting two 4k monitors to SEPARATE DP 1.2 ports.
The questions is whether replacing two UP3214Q (which supports 4k@60hz in MST mode) with two P2415Q (which supports 4k@60hz in SST mode) will solve the problem.
I apologize for the misunderstanding.
I read jayburd tested configurations and also read both UP3214Q & P2415Q users' manuals, and to be honest with you, I was unable to find any reason why he was unable to use both displays at the same time, the only components that come to my mind are the DP cables because they weren't confirmed.
You should be able to display 3840 x 2160 @ 60 Hz in both monitors, no matter if they are UP3214Q (with DP 1.2 enabled) or P2415Q.
Thank you for digging into the problem!
There is a potential reason why UP3214Q might not work:
The way 4k@60hz work in MST mode is by splitting the screen into two (1920x2160@60hz?) halves then the image is merged at the monitor.
Therefore while there are only two physical monitors each monitor is running on two streams this effectively gives 4 logical monitors simutaneously.
Now the spec for the integrated graphics says it only supports a maximum of 3 monitors. So if you have the resource to check with the people who have precise information what this means? Besides sylvia said they escalated the problem to the engineers so what was the outcome?
That said, I'm not writing a Master's thesis on monitor (in)compatibility. If you have the facility to actually test two P2415Q or any recent 4k monitors with SST support it will be very very helpful.
BTW as long as what jayburd describe was credible the DP cable could be ruled out. He had no problem running any of those two monitors as long as it other one is not up. The problem is pronounced only when he try to enable MST on both monitors.
Thank you for your input.
I did some further research and tested the following:
Intel® NUC Kit NUC5i5MYHE
Latest Intel® HD Graphics 5500 Version: 126.96.36.19924 (Latest) Date: 3/30/2017
Windows® 10 Pro 64 Bit
HP Z27s & LG 55UH8500
Straight video connection from the Intel® NUC to the HP Z27S and used an adapter from mDP to HDMI to connect the LG TV.
I was able to display 3840x2160 @60 Hz on both displays at the same time.