Display port 1.1a daisy chain'able?

[colin_p]

I hope someone knows and can help.

I have a gracefully ageing laptop which has a 32bit version Win10 on it as I need to run some 32 bit only software (it won't work on a 64 bit machine).

The lovely old laptop is an HP Elitebook 8470p, specs in link below

https://support.hp.com/us-en/document/c03374369

In the specifications, it is listed that;


DisplayPort

• Supports resolutions up to 2560 x 1600, 30-bit color depth at 60 Hz, and full HD (1920 x 1080) monitors, 24-bit color depth at 120 Hz

and

• DisplayPort - One (UMA: v1.1a; discrete: v1.2)

It doesn't have a 'discrete' dedicated graphics card so will run v1.1a, not v1.2


I've spent a fair amount of time scouring the internet and have come to the conclusion that there is very little info on what is very old tech / standards.

I can run a 1080p television with a display port to hdmi cable but..

My question is;

I'd like to run duel monitors and was wondering if v1.1a will allow daisy chaining?

The other option, which I'm not sure will work is to plug one monitor into the display port and one into the VGA socket (it is an old laptop!)


Any thoughts, advice or suggestions more than welcomed. Buying a newer laptop to run a single bit of software isn't justifiable.

Many thanks

[mmm-five]

Not sure DP1.1a has enough bandwidth, never mind the capability, and you would also need a monitor that supported daisy-chaining / pass-through?

Thought I might be able to help you out with an old HP dock/hub for my old Elitebook, but forgot that I'd handed it over when I swapped to a Z-Book (and that hub won't work with your machine).

[xeny]

My experience of 3rd gen Core processors (which is what your link says it has) is that they are reluctant to drive two external displays from a laptop.

You've not got access to a monitor to try simultaneously over VGA with the TV coming from the DP output?

I believe daisy chaining was added with DP 1.2, it isn't there in 1.1.

If all else fails, you could use a DisplayLink USB dock.

[theboss]

MST (daisy-chaining) was introduced in DP1.2 so I suspect it won't work.

[colin_p]

Gents,

Thank you.

Seems like I'll have to put up with a single monitor.

[paulrockliffe]

You can run a DisplayPort splitter I think, you'll be limited by the lower of the maximum resolution x refresh rate of the graphics card or the max of the cable standard, but a splitter will happily knock 60Hz down to 30Hz to let you run two screens if you don't have the capacity to cover the resolution of your screen x 2.

[colin_p]

Thanks Paul.

I'm going to go DP to DP on one monitor.

And try VGA to VGA on another.

If it works, it work, if it doesn't, so be it. It is not graphics intensive stuff.

[xeny]

paulrockliffe said:

You can run a DisplayPort splitter I think, you'll be limited by the lower of the maximum resolution x refresh rate of the graphics card or the max of the cable standard, but a splitter will happily knock 60Hz down to 30Hz to let you run two screens if you don't have the capacity to cover the resolution of your screen x 2.

I think the DP splitters rely on the GPU supporting MST don't they?

[colin_p]

For some closure;

The answer is no. I didn't try daisy chaining via the DP but did try one DP and one VGA, nope, not at the same time.

[paulrockliffe]

xeny said:

I think the DP splitters rely on the GPU supporting MST don't they?

I don't know? I have mine plugged into USB, so I assumed it was doing some USB thing with Windows.

[xeny]

paulrockliffe said:

I don't know? I have mine plugged into USB, so I assumed it was doing some USB thing with Windows.

I'd have thought that was a DisplayLink device which happens to have DP outputs ?

[paulrockliffe]

Maybe, I called it a splitter because it splits 1 DP signal to two monitors.

[eltawater]

What resolution monitors are you planning to use?

The specs for your laptop indicate that you may have USB 3 connectors available, so you have the option of using either the HP port replicator like the HP 3005PR or one of the generic USB 3 to HDMI/DP adapters you can find on Amazon. Typically these may be limited to either HD resolution-ish of 1920x1200 / 1920x1080 so watch out if you're planning on connecting to a 4K monitor.

If you're only planning on running dual monitors in HD resolutions then there's no need for a USB 3 to dual monitor adapter as that effectively gives you 3 connections, a USB 3 to single monitor adapter will be fine. You should be able to run the displayport from your laptop to monitor 1 and then the USB 3 to monitor 2 simultaneously.

I've previously achieved this with Dell laptop using onboard HDMI and a USB 2 to monitor adapter for dual screens in the past. I'm currently staring at 4 screens where two of them are running off an HP 3005PR port replicator using HDMI and Displayport, it was previously connected to a displaylink equipped USB 3 dock with HDMI and DVI connections.

[anonymous-user]

FWIW I run two 30” monitors each at 2560x1600, from one DisplayPort on the PC, daisy chaining one monitor to the next.

ISTR I had to set the monitors to DisplayPort 1.4 to get them to run.

[colin_p]

eltawater said:

What resolution monitors are you planning to use?

The specs for your laptop indicate that you may have USB 3 connectors available, so you have the option of using either the HP port replicator like the HP 3005PR or one of the generic USB 3 to HDMI/DP adapters you can find on Amazon. Typically these may be limited to either HD resolution-ish of 1920x1200 / 1920x1080 so watch out if you're planning on connecting to a 4K monitor.

If you're only planning on running dual monitors in HD resolutions then there's no need for a USB 3 to dual monitor adapter as that effectively gives you 3 connections, a USB 3 to single monitor adapter will be fine. You should be able to run the displayport from your laptop to monitor 1 and then the USB 3 to monitor 2 simultaneously.

I've previously achieved this with Dell laptop using onboard HDMI and a USB 2 to monitor adapter for dual screens in the past. I'm currently staring at 4 screens where two of them are running off an HP 3005PR port replicator using HDMI and Displayport, it was previously connected to a displaylink equipped USB 3 dock with HDMI and DVI connections.

Thank you Eltawater, and to everyone else.

From your advice I took a punt on a USB 3 to twin HDMI gadget, Amazon sometimes comes in very handy.

Plugged it in expecting it not to work or at least some faffage, but it just worked, straight out of the box.

I punted for one that allegedly does a bit of graphics processing so £45, but solved the problem without fuss.

Thank you again.

[edit] link to gadget

https://www.amazon.co.uk/dp/B0725K1MHH?ref_=pe_270...

Edited by colin_p on Sunday 9th July 17:30

Edited by colin_p on Sunday 9th July 17:31

[TonyRPH]

I realise you have resolved this - however your laptop has three display outputs.

DisplayPort, VGA and DVI-D

You should be able to use at least two of those simultaneously (if not all three!).

So you could connect one monitor with DisplayPort, and the other with either VGA or DVI (if the monitor has either of those ports).

Windows should then just detect the second monitor automatically.

[eltawater]

colin_p said:

Thank you Eltawater, and to everyone else.

From your advice I took a punt on a USB 3 to twin HDMI gadget, Amazon sometimes comes in very handy.

Plugged it in expecting it not to work or at least some faffage, but it just worked, straight out of the box.

I punted for one that allegedly does a bit of graphics processing so £45, but solved the problem without fuss.

Thank you again.

[edit] link to gadget

https://www.amazon.co.uk/dp/B0725K1MHH?ref_=pe_270...

Edited by colin_p on Sunday 9th July 17:30

Edited by colin_p on Sunday 9th July 17:31

Glad it's all working for you now!