daisy chain monitors with hdmi

[alme55]

I have a Dell-XPS 13 (2015) laptop that only has one mini-display-out, currently i am using a 27" Acer K272HUL 1440p monitor with a mini-displayport to displayport cable, i got a second 27" 1080p monitor i want to use but it only has an hdmi and a dvi-port, no displayport, the acer monitor has a dp-out port built in so i can daisy chain another monitor to it.

What i want to know is, would i be able to daisy chain the 1080p monitor with a Dp to Hdmi cable, or does both monitors have to have displayport to work with daisy chaining.

[spwath]

it should work

 

actualy I have no idea

[79wjd]

afaik only DP supports daiy chaining, although I guess if you're outputting on DP and using an adapter to convert to HDMI then it should be the same thing...no? 

[alme55]

thats what i was thinking, i just wanted to make sure before i spend money on the dp to hdmi cable

[Oshino Shinobu]

It should work, as far as I know it operates as  an MST hub, which should be able to be converted to HDMI. 

 

Notice a lot of shoulds in there. I've never actually tried it myself. 

[alme55]

i will just order the cable and get back if it does or doesn't work, if it doesn't work i will return it. Thanks for the input.

[Glenwing]

That won't work unfortunately, all monitors in a daisy-chain must be DisplayPort. For a DP-to-HDMI cable to work the DisplayPort controller at the source needs to basically switch to "HDMI mode" where it outputs HDMI signals instead of DisplayPort. However for they daisy-chain to work in the first place the DP controller needs to be in DisplayPort mode, so no adapters are possible in a chain.

[alme55]

That won't work unfortunately, all monitors in a daisy-chain must be DisplayPort. For a DP-to-HDMI cable to work the DisplayPort controller at the source needs to basically switch to "HDMI mode" where it outputs HDMI signals instead of DisplayPort. However for they daisy-chain to work in the first place the DP controller needs to be in DisplayPort mode, so no adapters are possible in a chain.

I just got the cable today and tested it and as you said it didn't work.  A bit disappointing,  I will just have to look for a mini-dp splitter I guess.

[79wjd]

That won't work unfortunately, all monitors in a daisy-chain must be DisplayPort. For a DP-to-HDMI cable to work the DisplayPort controller at the source needs to basically switch to "HDMI mode" where it outputs HDMI signals instead of DisplayPort. However for they daisy-chain to work in the first place the DP controller needs to be in DisplayPort mode, so no adapters are possible in a chain.

Wait, but why wouldn't that work exactly? Shouldn't the signal still be outputted as a DP signal and then only converted to an HDMI signal as it arrives at the second monitor? I.e. isn't it a valid signal as soon as it leaves the DP output on the first monitor? 

[alme55]

I thought the same thing, but as Glenwing said "the DisplayPort controller at the source needs to basically switch to "HDMI mode" where it outputs HDMI signals instead of DisplayPort", if i am reading that correctly that means it is sending an hdmi signal from the dp out on the monitor, it isn't sending a dp signal that is converted as it reaches the second monitor, rather it is already converted to an hdmi signal before it leaves the first.

[79wjd]

I thought the same thing, but as Glenwing said "the DisplayPort controller at the source needs to basically switch to "HDMI mode" where it outputs HDMI signals instead of DisplayPort", if i am reading that correctly that means it is sending an hdmi signal from the dp out on the monitor, it isn't sending a dp signal that is converted as it reaches the second monitor, rather it is already converted to an hdmi signal before it leaves the first.

Except an active DP to HDMI cable would convert the signal from DP to HDMI when it reaches the converter, not when it leaves the device (no?)? 

[alme55]

The reason i even asked this is i tried to research it and couldn't find much of anything on how daisy chaining actually worked, only people showing how to set it up.  Some say the last monitor in the line can use a converter and some say it won't work.  I found this on amd's page for daisy chaning "No, the last monitor in the chain can does not need to support DisplayPort 1.2 Multi-Stream Transport (MST)."

What i will do is return the cable i got and try a different one and see if that works, if that doesn't work, then i was thinking maybe a display signal isn't all that is sent through the cable while daisy chaining and the converter breaks that other signal, just a guess though.

[79wjd]

The reason i even asked this is i tried to research it and couldn't find much of anything on how daisy chaining actually worked, only people showing how to set it up.  Some say the last monitor in the line can use a converter and some say it won't work.  I found this on amd's page for daisy chaning "No, the last monitor in the chain can does not need to support DisplayPort 1.2 Multi-Stream Transport (MST)."

What i will do is return the cable i got and try a different one and see if that works, if that doesn't work, then i was thinking maybe a display signal isn't all that is sent through the cable while daisy chaining and the converter breaks that other signal, just a guess though.

Out of idle curiosity, did you pick up n active or passive cable? 

[Glenwing]

Wait, but why wouldn't that work exactly? Shouldn't the signal still be outputted as a DP signal and then only converted to an HDMI signal as it arrives at the second monitor? I.e. isn't it a valid signal as soon as it leaves the DP output on the first monitor? 

 

We're not talking about signal converters here, a simple DP-to-HDMI cable won't convert any signals.

[79wjd]

We're not talking about signal converters here, a simple DP-to-HDMI cable won't convert any signals.

An active cable would though, wouldn't it? (that's what I was initially thinking the whole time -- I thought you needed an active cable to go from DP to HDMI anyway)

[Glenwing]

An active cable would though, wouldn't it? (that's what I was initially thinking the whole time -- I thought you needed an active cable to go from DP to HDMI anyway)

 

Yes that should work in theory, but converters to tend to be finicky so it's not a guarantee. You can use a passive cable from DP to HDMI, just not from HDMI to DP.

[79wjd]

You can use a passive cable from DP to HDMI, just not from HDMI to DP.

ahhh

[alme55]

it's just a dp to hdmi passive cable, wasn't looking to spend $90 on just a converter, anyway bought another cable and it still didn't work, so i will just have to get more expensive active mini-dp splitter and use that directly from the laptop.