MacBook Air M5: External screens mirroring, cannot set up

AndyTown78 wrote:

im trying to do this at work and perhaps the hub here isn't correct but I did buy monitors etc to set uo a hime work station for my daughter and I both to use and bought this hub with 2 4K monitors.

can you tell me if this will work with 2 monitors its usb C with 2 HDMI and power supply.

Lemorele 13 in 1 USB C Docking Station Dual Monitor, Dock Hub Multiport Adapter Triple Monitor to 2 HDMI 4K,VGA,5 3.0/2.0,USB 3.0,PD,SD/TF,3.5MM for Lenovo,Surface,MacBook Laptops

That description appears to match this Lemorele dock on Amazon, or something very much like it.

https://www.amazon.com/Lemorele-Docking-Station-Monitor-Multiport/dp/B0C3CV46DT?th=1

For this particular dock, if you scroll down to the section that shows "Mac OS Display Modes", you'll see that all three external monitors (VGA + 2 HDMI) show the same picture in either "Mirror Mode" or "Extended Mode". In the description, it says "Notices:MacOs laptop only support SST mode, so all external monitor screens will be the same."

So the dock to which I linked (identified as a TC200 docking station, somewhere in the description) wouldn't do what you want. I suspect the same is true of all other Lemorele docks.

On the manufacturer's site, I see no evidence that Lemorele makes any Thunderbolt products.

https://us.lemorele.com

Which suggests that all of the Lemorele docks with multiple display outputs are

• Using MST, which the Mac does not support, and/or
• Using a second-class workaround such as DisplayLink, which requires installation of a special driver

In that, they would be like many other "dime a dozen" dock vendors.

-----

Several manufacturers that do make Thunderbolt docks, hubs, and dual-display adapters:

• Other World Computing
• SonnetTech
• CalDigit

Dell and HP also make some Thunderbolt docks, but their support tends to be, shall we say, not as Mac-oriented. Some of the Dell and HP docks that use Thunderbolt also use MST, which can make for an "interesting" time for Mac users trying to figure out which pairs of outputs will support extended desktop mode.

The M5 MacBook Air has Thunderbolt 4 – so while it would work with Thunderbolt 3, 4, and 5 docks, it would not be able to take advantage of any extra capabilities that Thunderbolt 5 offers vs. Thunderbolt 3 and 4.

-----

An alternative would be to use a plain USB-C dock with the M5 MacBook Air, plug one monitor into the dock, and plug the other monitor directly into the M5 MacBook Airs other USB-C (DisplayPort, Thunderbolt) port – with the aid of a USB-C to {DisplayPort, HDMI, etc.} adapter or adapter cable, if needed.

How are you connecting the two external displays to the Mac?

If you are using a "plain" USB-C dock – not a Thunderbolt hub or dock – and connecting both external displays to it, that could be the problem.

Macs do not support DisplayPort MST and will only send one signal over a plain USB-C (DisplayPort Alt Mode) link. If a USB-C dock or hub relies on DisplayPort MST to drive two monitors, the typical symptoms are that

• The dock or hub will present the same video signal to both monitors
• The monitors will appear to "mirror" each other
• The Mac will only see one of the monitors

If this is the problem, solutions include

• Plugging one of the monitors into a separate USB-C host port on the Mac (possibly with the aid of an adapter), or
• Replacing the plain USB-C hub/dock with a Thunderbolt one. Three long-time suppliers of Thunderbolt docks for Mac users are Other World Computing (MacSales), SonnetTech, and CalDigit.

If your displays are connected through different USB-C host ports – or are connected through a Thunderbolt dock, hub, or dual-display adapter, see

Extend or mirror your Mac desktop across multiple displays - Apple Support (CA)

AndyTown78 wrote:

great thanks got the orientation sorted MacBook to the right but its still only mirroring, the two monitors showing the same. one of the reasons I bought this one was said can use 3 screens is this not possible? maybe I have it set up wrong through the hub. the hub works fine with the windows laptop

From Apple's Technical Specifications for the 15" M5 MacBook Air (emphasis mine):

----------

Supports up to two external displays:

• Two displays up to a native resolution of 6K at 60Hz or 4K at 144Hz
• One display up to a native resolution of 8K at 60Hz or 5K at 120Hz or 4K at 240Hz

Supports up to two external displays over a single Thunderbolt port

Simultaneously supports the built-in display at full native resolution

Thunderbolt 4 (USB‑C) ports support native DisplayPort 1.4 speeds (up to HBR3) with DSC capability

----------

My guess is that we're looking at a plain USB-C hub that relies on MST, and that this is the issue. Windows might support that use of MST, but Macs don't. The M5 MacBook Air can drive up to two external displays at the same time as the built-in screen, but only if you connect the displays through different host ports, or bring Thunderbolt into the picture.

AndyTown78 wrote:

one of the reasons I bought this one was said can use 3 screens is this not possible? maybe I have it set up wrong through the hub. the hub works fine with the windows laptop

the internal screen and two external? it does appear that is possible with that Mac.

see if anything here helps you. Use external monitors with your Mac - Apple Support

you can go into System Settings > Displays and click the "arrange" button, then drag the displays into your desired arrangement.