Multiple monitors through a single Thunderbolt port

[szilske]

Hey there, I got a M1Pro MacBook Pro and I have two Monitors, which I can connect via HDMI. I bought a cheap USB-C hub on Amazon that has two HDMI ports.

When I connect all that to my MacBook, both monitors are recognized as only one display by macOS and they display the same image. On my wife's Dell Windows that works totally fine, so I think the hub is capable enough.

What can I do? Are there any Mac specific requirements?

Cheers!

 

[joevt]

The USB-C hub uses a MST hub to support multiple displays. macOS doesn't support separate multiple displays using MST - it will only support mirrored mode.
You can connect a DisplayLink USB adapter to the USB-C hub but DisplayLink uses USB to transmit compressed video (16 Gbps compressed to 1 Gbps) to display video.
The best option is a Thunderbolt dock or hub which can support two displays. If the displays have DisplayPort inputs, then use USB-C to DisplayPort cables.

 

[szilske]

The USB-C hub uses a MST hub to support multiple displays. macOS doesn't support separate multiple displays using MST - it will only support mirrored mode.
You can connect a DisplayLink USB adapter to the USB-C hub but DisplayLink uses USB to transmit compressed video (16 Gbps compressed to 1 Gbps) to display video.
The best option is a Thunderbolt dock or hub which can support two displays. If the displays have DisplayPort inputs, then use USB-C to DisplayPort cables.

Sounds reasonable. Can you recommend a Thunderbolt dock which will also work with Windows machines?

 

[Sweetfeld28]

We use the Dell D6000, or the HP G5 docks here at work; which are both Thunderbolt 3.

 

[joevt]

Can you recommend a Thunderbolt dock which will also work with Windows machines?

Does your Windows machines have Thunderbolt? Thunderbolt 3 or Thunderbolt 4? Windows Thunderbolt 3 machines might work with Thunderbolt 4 devices - you have to check what Thunderbolt controller it has.
https://www.caldigit.com/caldigit-t...hub-compatibility-and-limitations-on-windows/

 

[szilske]

Does your Windows machines have Thunderbolt? Thunderbolt 3 or Thunderbolt 4? Windows Thunderbolt 3 machines might work with Thunderbolt 4 devices - you have to check what Thunderbolt controller it has.
https://www.caldigit.com/caldigit-t...hub-compatibility-and-limitations-on-windows/

Not sure actually. I will have to check. I doubt that they have Thunderbolt 4. Thanks for the heads-up.

 

[szilske]

We use the Dell D6000, or the HP G5 docks here at work; which are both Thunderbolt 3.

HP G5 looks nice, seems to be not so awfully big. Colleagues recommended the Lenovo AF40 but that thing is huge!

 

[Sweetfeld28]

HP G5 looks nice, seems to be not so awfully big. Colleagues recommended the Lenovo AF40 but that thing is huge!

Yeah they have some bigger models now, but the G5 seems to do ok for us.

I personally have the OWC Thunderbolt 3 v1 Dock, but it is ok.

 

[szilske]

HP G5 does not work, at least not the version here in Europe. No DisplayLink support, I assume.

I will now go for the Lenovo.

 

[Sweetfeld28]

HP G5 does not work, at least not the version here in Europe. No DisplayLink support, I assume.

I will now go for the Lenovo.

Have you installed the driver on your PC?? DisplayLink Driver download

 

[szilske]

Yes, but the screen is still only mirrored on both displays. It seems that the G2 has DisplayLink, but the G5 seems not to support it.

 

[joevt]

Yes, but the screen is still only mirrored on both displays. It seems that the G2 has DisplayLink, but the G5 seems not to support it.

Do you mean HP Thunderbolt Dock G2? The HP Thunderbolt Dock G2 doesn't have DisplayLink. It uses Thunderbolt. It has a 3 port MST hub for the two DisplayPort ports and the USB-C with DisplayPort Alt Mode port. The USB-C with DisplayPort Alt Mode port is switched with the VGA port if a VGA display is connected but can still be used for USB.
For macOS, you can connect one display to downstream Thunderbolt port and a second display to one of the MST hub ports.

The HP USB-C Dock G5 is just a dock with a built-in MST hub. It cannot be used to connect two displays to macOS. I don't see any mention of DisplayLink in the user manual or in the software downloads or anywhere.

In either case, the MST hub of the G2 and G5 can connect multiple displays only for Windows or Linux, not macOS.

 

[szilske]

Great explanation, thanks! It seems I have no idea how these docks actually work 😅

I will go for the Lenovo 40AF now, which has DisplayLink and should work fine with both my MacBook and the family's Windows machines as well. If I went for a full-blown Thunderbolt dock, I'm afraid it might not work with older systems.

 

[Richard10250]

Great explanation, thanks! It seems I have no idea how these docks actually work 😅

I will go for the Lenovo 40AF now, which has DisplayLink and should work fine with both my MacBook and the family's Windows machines as well. If I went for a full-blown Thunderbolt dock, I'm afraid it might not work with older systems.

For what its worth, I can share that I use a Lenovo ThinkPad Hybrid USB-C with USB-A Dock (Type 40AF) successfully with both my Lenovo T14 laptop and my MBA M2 15 inch (2023) using the DisplayLink driver. I achieve two indepdent displays (both 2560x1440 @ 120Hz in my case) while in clamsheel mode with no challenges. Its mostly a simple TB cable swap between my work Lenovo to my private MBA. The only negative is that it cannot display copy protected video such as Netflix moview via DisplayLink.