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benomatis

macrumors newbie
Original poster
Oct 25, 2016
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Stephen.R

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Nov 2, 2018
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I'm guessing the DP > Dual DP adapter makes use of DisplayPort MST, (the same way you can daisy-chain some DisplayPort monitors). My understanding is that support for this technology is a bit hit-and-miss under macOS. I abandoned any plans to use it when I discovered my Dell P2415Q's would instantly drop to 30Hz when using this mode, and bought a TB3 to dual DP adapter (instead of daisy chaining).

So short answer: it might work (I notice Lenovo say "two identical monitors" so that may be an issue if the resolution of them is different). Another alternative might be to use the regular DP out on the Dock, and get a USB-C to DP cable and use it from the second TB3 port.
 

benomatis

macrumors newbie
Original poster
Oct 25, 2016
7
0
I'm guessing the DP > Dual DP adapter makes use of DisplayPort MST, (the same way you can daisy-chain some DisplayPort monitors). My understanding is that support for this technology is a bit hit-and-miss under macOS. I abandoned any plans to use it when I discovered my Dell P2415Q's would instantly drop to 30Hz when using this mode, and bought a TB3 to dual DP adapter (instead of daisy chaining).

So short answer: it might work (I notice Lenovo say "two identical monitors" so that may be an issue if the resolution of them is different). Another alternative might be to use the regular DP out on the Dock, and get a USB-C to DP cable and use it from the second TB3 port.

I don't understand: why would I need to daisy-chain? It's a DP to Dual DP, so I can just hook the 2 monitors up to the adapter with 2 DP slots in it, and it is working fine right now with a Dell docking station that has a single DP port.

So the question really is: is there any technical limitation with the Belkin dock actually supporting the DP to Dual DP adapter.
 

Stephen.R

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Nov 2, 2018
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I don't understand: why would I need to daisy-chain?
You don't, but I suspect it works on the same concept, the only difference is that the 'smarts' to split the two DP signals on the single cable, are in that little Lenovo adapter, rather than in the back of a monitor (as it would be if you used daisy-chaining)

and it is working fine right now with a Dell docking station that has a single DP port
Right, but my point was that MST (which allows sending 2 DP streams over a single DP cable) is, AFAIK not well supported by macOS.
 

benomatis

macrumors newbie
Original poster
Oct 25, 2016
7
0
my point was that MST (which allows sending 2 DP streams over a single DP cable) is, AFAIK not well supported by macOS.

Ok, thank you, that's why I'm a little hesitant with this now, but it would be just so great if it was really just that easy.

In the meantime, I also got feedback from an Apple reseller (selling the Belkin dock), and they are saying that they are certain the dock and the adaptor would work well together because both support DP 1.2.
 

Stephen.R

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Nov 2, 2018
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If you have the Lenovo adapter already, I'd just try it - I expect the issue (if there is one) will be macOS rather than the dock hardware.
 

benomatis

macrumors newbie
Original poster
Oct 25, 2016
7
0
If you have the Lenovo adapter already, I'd just try it - I expect the issue (if there is one) will be macOS rather than the dock hardware.

Well, for that I'd have to get the dock at least, wouldn't I? The problem is that this is now the deciding factor on whether or not my boss will approve the purchase of a MacBook Pro as a company laptop (and the dock). If it's not guaranteed to work like this, it'd probably not be approved.

Is there really no actual technical spec I could check that would, for sure, tell us if it would or would not work?

By the way, I got feedback from another reseller, this one says that it's "not guaranteed" to work, significantly less positive compared to the previous one. :)
 

Stephen.R

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Nov 2, 2018
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The problem is that this is now the deciding factor between my boss approving to get the MacBook Pro as a company laptop (and the dock), or getting a Windows machine.

Is it just about the ability to drive two displays from the Dock? Presumably that Lenovo one you have now would stay with the Dell (?) dock you have now, and they just want to know if you can drive two displays from the Dock, right?

If that's the case, yes you can drive two displays: either using the native DP + a USB-C to DP cable, or using a TB3 to Dual DP adapter (which is what I have) like https://eshop.macsales.com/item/OWC/TB3ADP2DP
[doublepost=1557327206][/doublepost]
Is there really no actual technical spec I could check that would, for sure, tell us if it would or would not work?

I think the problem is that some parts of specs like this are optional, or like in my case: the displays support MST for daisy-chaining, but they drop to 30Hz, which isn't great, but they "support it".
 

benomatis

macrumors newbie
Original poster
Oct 25, 2016
7
0
Is it just about the ability to drive two displays from the Dock?

Yes, more exactly the company obviously would like to save by not having to buy me 2 new monitors, just because I want a mac, although on a separate note I told my boss I really would like to ensure at least one of them is replaced so I have identical ones (for various reasons, nonetheless that the Dell is Full HD while the Lenovo is not, and is anyways subpar quality compared to the Dell, despite its age).

Presumably that Lenovo one you have now would stay with the Dell (?) dock you have now, and they just want to know if you can drive two displays from the Dock, right?

Ideally, for the company (and their "wallet"), I could just keep the current monitors and adapter, and just hook it up to the mac. I'd definitely like to have a dock, just like I have one now for my Dell laptop, so that's a given.

...you can drive two displays: either using the native DP + a USB-C to DP cable or using a TB3 to Dual DP adapter...

I see what you mean, I really just wanted to save on having to buy yet another adapter if this one worked, so I guess I could just try this out, and if it's not working, I could buy just one more.

I think the problem is that some parts of specs like this are optional, or like in my case: the displays support MST for daisy-chaining, but they drop to 30Hz, which isn't great, but they "support it".

The TB3 to Dual DP adapter you have, couldn't that potentially(!) have the same disadvantage with my current monitors?
 

Stephen.R

Suspended
Nov 2, 2018
4,356
4,747
Thailand
Ideally, for the company (and their "wallet"), I could just keep the current monitors and adapter, and just hook it up to the mac. I'd definitely like to have a dock, just like I have one now for my Dell laptop, so that's a given.

In your position I'd probably just use the DP + get a USB-C to DP cable. One like https://eshop.macsales.com/shop/docks/owc-thunderbolt-3-dock is cheaper than the Belkin, and the cost of the cable should be minimal.

I really just wanted to save on having to buy yet another adapter if this one worked
I mean technically it's just a different cable - they start at about $10.

Ideally, for the company (and their "wallet"), I could just keep the current monitors and adapter, and just hook it up to the mac. I'd definitely like to have a dock, just like I have one now for my Dell laptop, so that's a given.
The OWC dock above is $50 cheaper (with more ports) and a USB-C to DP cable is ~$10, and then someone else (in the company) can keep using your laptop+dock+adapter, presumably?

The TB3 to Dual DP adapter you have, couldn't that potentially(!) have the same disadvantage with my current monitors?
No, it doesn't rely on MST, it's sending the DP signal over TB3 (it's an active adapter, not passive).
 

benomatis

macrumors newbie
Original poster
Oct 25, 2016
7
0
The OWC dock above is $50 cheaper (with more ports) and a USB-C to DP cable is ~$10, and then someone else (in the company) can keep using your laptop+dock+adapter, presumably?

With that dock, I'd need 2 cables, actually, one mini DP to DP, and one TB3 to DP, but you're right, they're relatively cheap.

No, it doesn't rely on MST, it's sending the DP signal over TB3 (it's an active adapter, not passive).

So isn't it just that I'd need to find out if my Belkin DP to Dual DP adapter actually relied on MST?
 

Roxy.music

macrumors 6502a
Jun 9, 2019
862
90
uk
In your position I'd probably just use the DP + get a USB-C to DP cable. One like https://eshop.macsales.com/shop/docks/owc-thunderbolt-3-dock is cheaper than the Belkin, and the cost of the cable should be minimal.


I mean technically it's just a different cable - they start at about $10.


The OWC dock above is $50 cheaper (with more ports) and a USB-C to DP cable is ~$10, and then someone else (in the company) can keep using your laptop+dock+adapter, presumably?


No, it doesn't rely on MST, it's sending the DP signal over TB3 (it's an active adapter, not passive).
[doublepost=1563206234][/doublepost]On the subject of OWC i am interested in one myself all be it a thunderbolt 2 one.
i see very few second hand and if i do see them they are all in the USA:(
 
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