User profile for user: pumping4ever
pumping4ever Author
User level: Level 1
10 points

MacBook Pro gets mirrored to two connected displays

I connected two HDMI Minotors 27 inch - LG 27UP850N


https://www.lg.com/de/monitore/lg-27up850n-w



They are connected via a Mokin USB Docking Station

https://www.amazon.de/MOKiN-Adapter-Docking-Station-Latitude/dp/B09MKG2L1F


My mac gets mirrored to both these monitors.

Tried the following

  1. Detect Display / Nothing happens
  2. uncheck mirroring / nothing happens
  3. mac os update / nothing happens
  4. changed dock / nothing happens


Will try the following


  1. remove dock and connect both monitors via USB C to the mac


Not sure if this would help but i would want a dock as they are meant for such things.


someone having faced the same issue please advise.



[Re-Titled by Moderator]

MacBook Pro (M2 Max, 2023)

Posted on Apr 17, 2023 6:31 AM

Reply
Question marked as Best reply
User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
129,889 points

Posted on Apr 17, 2023 9:46 AM

That USB-C dock is only capable of supporting ONE fully-hardware-accelerated display, because it is a USB-C Dock.


To support two displays, a Dock (or the first display) needs to be a genuine ThunderBolt device, on a genuine Thunderbolt cable out of the Mac.


--------

The Apple standard for its built-in hardware-accelerated displays, makes them suitable for full-motion video for production/display of cinema-quality video with NO dropped frames, and NO dropouts or partial-blank scan lines due to memory under-runs or other issues. This requires a hardware rasterizer/display-generator for each fully-accelerated display. 


If you are only doing program listing and stock quotes and other slow to change data, there are some other solutions, but they require you to make some strong compromises.

View in context

Similar questions

4 replies
Question marked as Best reply
User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
129,889 points

Apr 17, 2023 9:46 AM in response to pumping4ever

That USB-C dock is only capable of supporting ONE fully-hardware-accelerated display, because it is a USB-C Dock.


To support two displays, a Dock (or the first display) needs to be a genuine ThunderBolt device, on a genuine Thunderbolt cable out of the Mac.


--------

The Apple standard for its built-in hardware-accelerated displays, makes them suitable for full-motion video for production/display of cinema-quality video with NO dropped frames, and NO dropouts or partial-blank scan lines due to memory under-runs or other issues. This requires a hardware rasterizer/display-generator for each fully-accelerated display. 


If you are only doing program listing and stock quotes and other slow to change data, there are some other solutions, but they require you to make some strong compromises.

Reply
User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
129,889 points

Apr 17, 2023 7:22 AM in response to pumping4ever

The Mac only supports up to two displays on one cable when connecting via ThunderBolt to a genuine Thunderbolt device (dock or display)


That Dock device is a USB-C device, and since USB-C has only half the data pathways of Thunderbolt, that is expected behavior.


--------

from the ad you linked:


Important note: 


  • MacBook does not support dual HDMI for triple display. Only Mirro mode is supported. 
  • Important: 1. Please use an HDMI 2.0 cable or better. 2. The Intel DP1.4 does not comply with bandwidth standard and therefore only the MacBook DP1.4 can reach 4k@60Hz. 
  • Only supports mirror mode on a Mac OS and Chrome Book system.


Reply

MacBook Pro gets mirrored to two connected displays

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.
Learn more Sign up