HP Thunderbolt Dock G2 to Mac book pro

[JMC7919]

 Sorry I don't see a board that fits this product, so I'm going to post in Notebook Hardware...

Work provided me with this dock.  I use a Mac Book Pro, one of the newer ones with only USB-C ports.  All seems to work well except my two external monitor are mirroring each other, and the Mac only seem to recognise one monitor.

Has anyone encountered this?  Or is it a known incompatibility?  Thanks!

[IronBadger]

I have the same setup.  In my reasearch I have found that this is a limitation of the macOS and the way these docks do multiple monitors.  Many hubs out there use a feature of DisplayPort 1.2 called MST to run two monitors off a single connection.

Here is a thread on Mac Rumors that talks about it.

https://forums.macrumors.com/threads/can-someone-confirm-if-mst-displayport-daisy-chaining-works-on-...

If you search on "macOS and MST" you can see reports from all over that macOS High Sierra only supports MST in mirror mode.

[JMC7919]

We have another user on campus with the same setup and it works fine, meaning each monitor is an extension and not a mirror of eash other.  ??

Thanks for your post.

[IronBadger]

Interesting!

I will dig a bit deeper into this then. 

It is technically not supported by HP but I have been trying to get it to work for a while.

Are both MacBooks on the same version of macOS? 

I have really only test 10.13.6.

Are you both using the 120W or 230W version of the dock?

On teh working setup, are they using the two DP ports for the monitors or is one monitor Thunderbolt3?

[JMC7919]

My Mac Book Pro is the first version with all USB-C ports, his is probably the refreshed version as his is brand new.  We did note my discrete graphics card is the Radeon Pro 455 and his the Radeon Pro 555.

Other than that seems like everything else is the same, OS, monitors, cables...

[IronBadger]

OK.  I have the early 2016 MacBook Pro with TB3 Intel Iris 550.

What I just figured out after looking at how the ports are attached in the dock is that the the USB-C, DP1 and DP2 ports are all on the same bus and hub.  When two monitors are connected to any two of those ports the macOS will only recognize 1 monitor and then mirror the display of that monitor to the second.  I have found no way around this yet.  The macOS will not even recognize the second monitor is attached.  Even though it is mirrored, the second does not show in the System Profiler.

The TB3 port on the back is actually on a seperate bus.  It does also support DP alternate mode for USB-C though.  My particular monitor has a USB-C port that supports alternate mode for video as well.  If I connect the USB-C port off the TB3 port on the back to one monitor and then use a DP on the back to connect the other, I can get the macOS to recognize both monitors individually.  I then get the standard display options and no mirroring.

So, I end up with

Display 1 - TB3 Port on dock --> USB-C on monitor via TB3 cable

Display 2 - DP1 on dock --> DP on monitor via DP 1.2 cable

If your monitor does not have USB-C, perhaps you can try a USB-C to DP adapter on the TB3 port on the back of the hub along with one of the DP ports on the hub and see if that works for you. 

I am still curious to know exactly how your coworker has it set up and working.

EDIT:  What I did just discover though is that the diplay connected via USB-C (to the back TB3 port) will not be recognized until the OS is completely boots.  So, I have to boot the laptop with the screen open and log in.  Whenthe progress bar almost reaches the end the USB-C monitor will wake up.  This does not happen when I connect the display to the USB-C port on the back vs the TB3 port.

EDIT 2: Sorry....another reboot seems to have resolved the issue in Edit 1.  But thought I would leave it in case others experience the same.

[JMC7919]

They said all they did was hook it up and it worked.  Must be something different about the newer Mac Book Pros.  I'm curious why it works too.

[IronBadger]

I wish I had a newer MacBook to test.

But that really shouldnt make a difference as your card supports MST (even if the OS does not) and is more than adequate to drive two monitors.  And I can drive two if I connect like I previously stated.

I will keep digging and experimenting.  Will update this thread if I find anything new.

[JMC7919]

I'll see about grabbing a new MacBook before it's deployed and check it out more closely.

[JMC7919]

Tried a brand new MacBook Pro and get the same results, mirrored external monitors.  Guess I'll have to visit the working one to see whats different.