DisplayPort Daisy Chaining

[TheGeek2448]

I've got an AOC Q2963PM (the 29", 21:9 monitor) and an Acer H236HL and a 660Ti. The AOC has Display-Port in and out and the acer does not have Display-Port  I was wondering If I could connect the AOC with a Display-Port cable and use a Display-Port to HDMI or DVI adapter out of the AOC and into the Acer.

 

P.S.: (my Review of AOC Q2963PM) http://linustechtips.com/main/topic/13071-aoc-q2963pm/

[GoodBytes]

This is really new technology that just recently came out. So resource information on this is virtually none.

However, I do know that the last display can be DisplayPort version 1. So I don't see why not it will be a problem for you to do what you want to do.

However, I recommend using DVI instead of HDMI, as HDMI (based on my experience, and on multiple forum, including here) many times, HDMI doesn't work well with computers. It has to do with different versions, and not being a focus from the graphic card manufacturers to test it properly, as it seams. Also, HDMI was not really designed for computer usage, during its development. DVI is solid, and we know it works.

[TheGeek2448]

I've ordered a DisplayPort cable and I'll tell you if it works. :) Thanks for the reply!

[GoodBytes]

Thanks!

[Lyons]

Correct me if I'm wrong, but I'm quite sure for daisy chaining you need a Thunderbolt enabled mini Diplayport out, which the 660Ti certainly doesn't have, and it is currently only available on limited (and expensive) motherboards. Keep in mind having a mini Displayport out on your GPU or your motherboard does not mean you have thunderbolt or its features. Mini Displayport is simply used as the Thunderbolt interface because it is very versatile (can be a data or display connection, etc.). You must be using a Thunderbolt enabled component. You also cannot simply use a displayport cable for Thunderbolt applications. Thunderbolt cables are active cables (NOT passive like DVI/VGA/HDMI), which is why they are so expensive. Once again, Thunderbolt cables appear to just be a mini Displayport cable, but infact only use mDP as an interface. Pic attached is an opened up Thunderbolt cable showing the controller chip that is situated at each end (this is part of the Thunderbolt processing).

[Glenwing]

Thunderbolt isn't necessary for daisy chaining, it's part of the DisplayPort 1.2 spec.  The Dell U2413 for example supports daisy chaining via full-size DisplayPort connectors, not Thunderbolt (Under the two full-size DP connectors if you look closely you can see the labels DP In and DP Out):

 

[Lyons]

Cool, I didn't know they added that. I assume Thunderbolt is still necessary for daisy chaining with non-display devices? Not that Thunderbolt will ever take off anyway... When did GPUs move to the DP 1.2 spec?

[GoodBytes]

Thunderbolt is an PCI-E in a overpriced cable. I am sure it can have been made way cheaper (ie: no special chips needed on the device and wire).

Did you know that DisplayPort 1.2 support not only Video, Audio, but also Auxiliary. Auxiliary means anything that is supported by the monitor and/or graphic card.

For example, it can carry USB, or Ethernet (most likely USB will be popular as it would make more sense in a computer environment, but its too offer an entry for other purposes, like TV). So far, thought, I have not seen any GPU or monitor that uses auxiliary feature out of the DisplayPort 1.2.

[Glenwing]

Cool, I didn't know they added that. I assume Thunderbolt is still necessary for daisy chaining with non-display devices? Not that Thunderbolt will ever take off anyway... When did GPUs move to the DP 1.2 spec?

It's been there since long before Thunderbolt was out, that's where Thunderbolt gets its daisy chaining capabilities ;)  If you wanted to daisy chain a non-display like a hard drive cage or something you'd have to use thunderbolt anyway, since DisplayPort isn't used for anything except displays.

 

GPUs have had DP 1.2 since the Radeon HD 6000 series, pretty much all current devices are DP 1.2 compliant.

[TheGeek2448]

Ok, so I've tried DisplayPort into my AOC monitor and my DisplayPort to DVI adapter out of the AOC into the Acer and I got no signal to the Acer.

I have an Idea why it didn't work, though. I realized my adapter cable is a passive adapter. I've ordered an active DisplayPort to DVI adapter and will try that.

[tabuburn]

It's been there since long before Thunderbolt was out, that's where Thunderbolt gets its daisy chaining capabilities ;)  If you wanted to daisy chain a non-display like a hard drive cage or something you'd have to use thunderbolt anyway, since DisplayPort isn't used for anything except displays.

 

GPUs have had DP 1.2 since the Radeon HD 6000 series, pretty much all current devices are DP 1.2 compliant.

I'm curious as to whether DP has enough bandwidth to support multiple full HD displays in a daisy chain.

[GoodBytes]

Up to 4x 1920x1200 monitors apparently.

Or up to 2x 2560x1440 monitors. But I have not tried it.

[Glenwing]

It has twice as much as HDMI 1.4a so it can do at least dual monitors at 1080p 60Hz, not sure if more.  Provided you are using DisplayPort 1.2 compliant devices including cables.

[tabuburn]

Found this in AMD's support page after a little digging:

 

1600x900 @ 60Hz, 24bpp

Up to 4

1920x1080 @ 60Hz, 24bpp

Up to 4

2560x1440 @ 60Hz, 24bpp

Up to 2

2560x1600 @ 60Hz, 24bpp

Up to 2

 

 

 

 

I'm impressed. Based on this, you could get a 2560x1600 display running at 120Hz refresh rate easily with DP 1.2.

[GoodBytes]

Oh yes of course, DP is much advance compared to DVI and HDMI.

It also does 4K at 60Hz 24bpp , which HDMI can't do (nor DVI. Dual link DVI stops at 2560x1600 @ 60Hz 24bpp)

[tabuburn]

Oh yes of course, DP is much advance compared to DVI and HDMI.

It also does 4K at 60Hz 24bpp , which HDMI can't do (nor DVI. Dual link DVI stops at 2560x1600 @ 60Hz 24bpp)

I wouldn't be surprised if DP 1.3 would support 4K @ 120Hz considering it gained a 2x increase in bandwidth going from 1.1 to 1.2.

[TheGeek2448]

Well, I have an active DisplayPort to DVI adapter and it still isn't working :( Apparently daisy-chaining only works with multiple  native DisplayPort monitors.

[GoodBytes]

Ah well.

Well that information was VERY useful. I think we will all share it with others, for those who fall in the same situation as you.

Hopefully, you didn't spend too much on adapters.

[tabuburn]

Well, I have an active DisplayPort to DVI adapter and it still isn't working :( Apparently daisy-chaining only works with multiple  native DisplayPort monitors.

Did you try only using the DP to DVI adapter on the last display while the ones before it were DP?

[TheGeek2448]

I'm not following. My 660Ti only has 1 DisplayPort out. I was hoping to use the DisplayPort in and out on the AOC monitor to daisy-chain both the AOC monitor and the Acer off of one DisplayPort cable. Do you mean try running the Acer off of the active DisplayPort to DVI adapter out of the 660Ti?

[tabuburn]

Like this: 660Ti->DP->AOC 1->DP w/ DVI active adapter->AOC 2.

[TheGeek2448]

I don't have a 2nd AOC monitor. my 2nd monitor is an Acer that has no native DisplayPort input.

I've already tried 660Ti ->DP->AOC->Active DP to DVI Adapter-> Acer

[tabuburn]

Most likely then that the DP daisy chaining will only support DP inputs.

[TheGeek2448]

...Apparently daisy-chaining only works with multiple  native DisplayPort monitors.

[Ryzon]

 

...Apparently daisy-chaining only works with multiple  native DisplayPort monitors.

 

Any idea if this is still the case? I have a T440s so it has native 1.2 Displayport. First link would be a U2415 and the last either DVI or HDMI.

 

Thanks!