OS X Display Port Daisy Chaining

cotton31 · 20 Mar 2015 at 10:16

Hi,

I'm trying to find out whether OS X supports this? I'm under the impression that it does, but can't get it to work!

Deleted member 77746 · 20 Mar 2015 at 10:29

6. Can other video adapters be connected or "daisy-chained" to Apple Mini DisplayPort adapters?

No, you should not connect Apple Mini DisplayPort adapters to any other video adapters. Connect your computer directly to an external display via one Mini DisplayPort adapter.

https://support.apple.com/en-gb/HT204149

cotton31 · 20 Mar 2015 at 10:47

Yes my MacBook is connected directly to one display - that display is then connected to another display.

I think that the article you've linked to is talking about daisy-chaining adaptors e.g.
mDP to HDMI -> HDMI to DVI etc.

cotton31 · 22 Mar 2015 at 09:26

Anyone else had similar issues?

shiver · 22 Mar 2015 at 15:14

Daisy-chaining monitors works with Thunderbolt monitors only. Not MiniDP or DP

cotton31 · 22 Mar 2015 at 16:16

Even based on this?

shiver · 22 Mar 2015 at 17:33

So you've answered your own question

cotton31 · 22 Mar 2015 at 21:37

What?

That support document suggests that MST over DisplayPort is supported, but I can't get it to work on my machine?

Caged · 22 Mar 2015 at 23:28

What are you trying to do, and what Mac do you have?

You're being very vague which is why people are struggling. That article suggests MST support for specific Macs with specific 4K displays, it says nothing about MST support for multiple monitors.

shiver · 23 Mar 2015 at 09:30

Vague questions get vague answers

cotton31 · 23 Mar 2015 at 09:37

I have one of the new Early 2015 MacBook Pro's 13".

I'm trying to daisy-chain two Dell U2515H displays using MST over DisplayPort, but I'm just getting the same image duplicated on each screen.

I've seen online that other people have got this working, albeit with other MST-supporting machines - the 13" MBP was added to that support doc after it's recent release, the pre 2015 version wasn't supported...

cotton31 · 23 Mar 2015 at 09:38

shiver said:
Vague questions get vague answers

You didn't supply an answer though, you suggested I'd answered myself...

shiver · 23 Mar 2015 at 11:16

cotton31 said:
I have one of the new Early 2015 MacBook Pro's 13".

I'm trying to daisy-chain two Dell U2515H displays using MST over DisplayPort, but I'm just getting the same image duplicated on each screen.

I've seen online that other people have got this working, albeit with other MST-supporting machines - the 13" MBP was added to that support doc after it's recent release, the pre 2015 version wasn't supported...

Finally some details.

Potentially a firmware thing on that particular display so it may be worth contacting Dell.

On OS X, in display prefs > arrangement do you see the 2x Dell displays plus the internal display?

cotton31 · 23 Mar 2015 at 11:39

Ask and you shall receive

I did wonder about a firmware update so I'll look in to that.

In display prefs I only see the one Dell display...

shiver · 23 Mar 2015 at 11:43

cotton31 said:
Ask and you shall receive

I did wonder about a firmware update so I'll look in to that.

In display prefs I only see the one Dell display...

And in System Information > Graphics/Displays ?

May give a better idea how it's being interpreted by the OS.

Looking at some Dell threads this seems to be a fairly common thing with MST on Windows and OS X and has often been firmware related.

cotton31 · 23 Mar 2015 at 11:56

Yeah it shows the same in there.

I'll try a firmware update and see how that goes, unless you have any other ideas?

cotton31 · 23 Mar 2015 at 12:04

Are firmware updates usually done on the monitors themselves, or via a PC?

shiver · 23 Mar 2015 at 12:36

cotton31 said:
Are firmware updates usually done on the monitors themselves, or via a PC?

Dell being PC, I'd imagine it's a Windows exe