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I haven't found any documentation saying it's not possible, but I've been trying to find if daisy-chaining Mini DisplayPort-to-DisplayPort with successive monitors connected using DisplayPort.

So:

Source-out -> Mini DisplayPort -> mDP to DP adapter ->
Monitor 1 in -> DisplayPort
Then Monitors 2+ -> DisplayPort, so normal daisy-chaining at that point.

Does anyone know if this is possible and/or why it wouldn't be? This is assuming the full standards across the board, with DP 1.2a compliance on the DP's and mDP compliant to the 1.2a standard.

I'm thinking of, for source, something like a tablet or docking station that has just the one display out, necessitating either USB-to-display connection or not using more displays.

Matej
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3 Answers3

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Mini DP is just a different form factor, the wires are the same. So at the protocol level, there are no reasons whatsoever why this shouldn't work.

At the bare hardware level, the adapter means another contact point, so more opportunities for broken cables and/or bad contacts. Cabling is generally considered critical for DP.

You didn't ask for this but given you're in the planning phase, you probably want to know this:
DP daisy chaining critically depends on each monitor correctly handling Multi-Stream mode. Given that monitors that can do this are just starting to become mass-market ware, this does not always work; for example, early revisions of Dell U2515H are known to be flaky.
The graphics card needs to be powerful enough to shove that many pixels out per second. Moderately powerful GPUs can handle that with ease, but the protocol chips between GPU and connector need to be designed for that load, too.

So: No guarantees at this time, though the situation is going to improve over the next few years as vendors react to complaints. If you order, order from a seller with a full-refunds-no-questions-asked policy.

Toolforger
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I have a Macbook Pro 2015 model and 2 K272HUL monitors that are chained. Macbook mini DP to Monitor 1 DP in -> Monitor 1 DP out to Monitor 2 DP in. Doesn't work. When I called Acer support, they said that it works fine on Windows but they haven't tested on Mac. When I called Apple Support (case #1107920040), they tried to reset and it didn't work. Since it's an inconvenience and nice to have, they said to use 1 thunderbolt per monitor and not chain them. I also noticed what was weird is that system information shows 2 monitors BUT they have the same serial number. I'm thinking that there is there is a bug in the software and it's just not fixed yet.

Albert T. Wong
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Hi I don't know if this will ever be fixed, but I don't understand why Apple has no idea about their own hardware. https://wikipedia.org/wiki/DisplayPort

"Daisy-chaining is a feature that must be specifically supported by each intermediary display; not all DisplayPort 1.2 devices support it. Daisy-chaining requires a dedicated DisplayPort output port on the display. Standard DisplayPort input ports found on most displays cannot be used as a daisy-chain output. Only the last display in the daisy-chain does not need to support the feature specifically or have a DP output port. DisplayPort 1.1 displays can also be connected to MST hubs, and can be part of a DisplayPort daisy-chain if it is the last display in the chain.

The host system's software also needs to support MST for hubs or daisy-chains to work. While Microsoft Windows environments have full support for it, Apple operating systems currently do not support MST hubs or DisplayPort daisy-chaining as of macOS 10.15 ("Catalina"). DisplayPort-to-DVI and DisplayPort-to-HDMI adapters/cables may or may not function from an MST output port; support for this depends on the specific device."

Best Regards

fabolous05
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