Active DP>HDMI adapters with DisplayPort MST


#1

Hi. I am looking to order two 2560x1440 monitors, which both support DisplayPort 1.2 MST (i.e. daisy chaining). I hope to pair these with my current 1920x1200 monitor via MST. However, this older monitor does not support DP at all.

Given that I hope to hook all three of these displays to a laptop DisplayPort output over USB-C (with a USB-C to DP cable connecting the laptop with the first monitor), and there aren’t any other video output ports on the laptop, am I able to use an active DP to HDMI converter to connect the last monitor to the chain? The converter would be from the 2nd monitor’s DP out, in order to connect to HDMI in on the last monitor.

The converter in question is http://plugable.com/products/dp-hdmi/.


#2

Oh, okay then :frowning:
Thanks for answering.


#3

Why does HDMI need to support MST? Only the protocol converter needs to support MST. It takes the MST signal, and outputs an HDMI signal. The problem is, you chose a converter that can’t do that?

The product page says the adapter supports DisplayPort 1.2. It doesn’t say if it works with MST.
http://plugable.com/products/dp-hdmi/

Other product pages do state that MST is not supported.
http://plugable.com/products/uga-4kdp

If the adapter doesn’t support MST, then maybe a “MST hub” would work?


#4

Hi Jgolds and joevt,

So, interesting update. Even though internal documentation indicates MST isn’t supported, I setup a quick test with 2 displays to see if the MST signal was able to be converted from the DP output of the first display in the chain. It worked!

Worth noting that MST implementations can behave differently, so there’s a very good chance this won’t work in all setups, but certainly worth a try.

Monitors used for testing: Dell U2415


#5

Absolutely fascinating! I just placed an order for one of your active adapters, for this exact use case.

Aside, a brief test confirms that a passive DP++ to HDMI adapter does not work for this scenario, as expected.


#6

Wow! Thanks. I hope to try this out!


#7

Confirmed, works!

Chomebook Plus -> Plugable USBC-DP adapter cable -> Dell Ultrasharp 2560x1440@60hz -> Plugable DP-HDMI rev B -> Non-Dell display 2560x1440@60hz.

Yes, Chromebook Plus drives the built-in screen plus two external screens - caveat Chromebook Plus limitation, the only option for the last display in the chain is Duplicate, not Extend.


#8

This is a reply to the reply above removed 2017-06-08


#9