Extended display vs. Mirroring with MacBook Pro 2020 M1 Running Sonoma 14.4.1

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Level 1

4 points

Extended display vs. Mirroring with MacBook Pro 2020 M1 Running Sonoma 14.4.1

I use a 32" Samsung HDTV, connected via HDMI, for my large-screen monitor. I would like to use both monitors with the Samsung as extended space where more windows could be moved to & from, as well as launched. I only am able to mirror the displays, and this only works when the Mac is plugged into power with the lid closed, or without power with the lid open. thus far, Apple support has not been able to help me with this issue, even at the local genius bar.

I have to connect the HDMI cable from the monitor to the Mac via a USB-C hub, which also allows for connection of USB-A devices. Another oddity is that power only charges the battery when plugged into the second USB-C port on the Mac, never via the USB-C power port on the hub.

Does anyone have some experience and suggestions on this?

Windows, Windows 6

Posted on Apr 23, 2024 1:04 PM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

142,375 points

Apr 24, 2024 9:08 AM in response to Jimm4448

To support more than one unique hardware-accelerated display on a Mac, the Port, the Cable, and the first device (dock or Display) must ALL be genuine ThunderBolt.

USB-C has far less bandwidth, and the Mac does not support multiple unique displays on ONE USB-C cable.

Using HDMI at high resolutions is like invoking black magic.

Resolutions above 4K REQUIRE that you connect directly, no adapters.

Connecting power to the Hub leaves you at the discretion of the Hub maker about whether or how much power is forwarded to the Mac.

which model M1 processor? M1 (plain) supports only ONE unique external display

M1 PRO supports two.

M1 MAX supports four

.

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Answer 2

Apr 24, 2024 9:43 AM in response to Jimm4448

How exactly (cables, adapters...) is the TV attached to the Mac?

You say "hub", but are not very explicit. Often we use the word "hub" meaning a device with multiple ports of the same kind, like USB. If that is the case, then a further adapter would be needed from USB to HDMI, and it is likely that this setup will not pass the proper video signals to your display.

It may be, though, that, instead, you are using a "dock" with multiple ports, including an HDMI port, and then an HDMI cable from that to the TV.

If this is the case, then it should "just work"...

Please clarify.

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Answer 3

Apr 24, 2024 10:09 AM in response to Jimm4448

It seems to me that it is working.

All you have to do is change from mirroring to extended desktop.

You can do it in System Settings->Displays.

And you can even do it on the fly, using the keyboard: Command-F1 toggles between extended desktop and mirroring.

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Answer 4

Apr 23, 2024 1:41 PM in response to Jimm4448

<<. the USB-C power port on the hub. >>

Wait, what? you did not say HUB. Every mention you made talks of DIRECT cable connections, nothing about HUBs.

Please restate your connections INCLUDING how the HUB is cabled into all this.

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Answer 5

Jimm4448 Author

Level 1

4 points

Apr 24, 2024 7:59 AM in response to Grant Bennet-Alder

Sorry I must not have been clear. Let me restate: EVERYTHING is connected via the USB-c hub, except for power. The hub is connected to one of the 2 USB-c ports on the Mac. In this case the hub is plugged into the FIRST USB-c port, and power into the SECOND USB-c port. (FIRST being the port closest to the hinged back of the MacBook.

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Answer 6

Jimm4448 Author

Level 1

4 points

Apr 24, 2024 10:03 AM in response to Luis Sequeira1

Thanks, Luis, for you reply to my questions. To attempt to answer yours: First, the Samsung TV is connected via an Acer 7 in 1 USB-C hub. The hub has HDMI, 2 USB-A, 2 USB-C, and 2 SD slots. The display on the TV is very good, perhaps not as sharp as on a $1500 Apple monitor, but it is more than good enough. The Apple support folks told me that I could have two active monitors, the built-in monitor and the external TV monitor, and they would act as one piece of screen real estate. They say I should be able to move windows/apps between the two monitors, but I can't find the settings or parameters that enable that to work. All I can do is mirror what is on the built-in monitor to the TV, so I am just using the TV as the single monitor for now, and keeping the lid closed on the Mac. It works, it's just not quite what I want and what Apple says I should be able to do.

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Answer 7

Jimm4448 Author

Level 1

4 points

Apr 24, 2024 10:10 AM in response to Grant Bennet-Alder

Grant, perhaps I am using the wrong term for the ports on my Mac. I guess they are Thunderbolt, and I don't understand the distinction between that and USB-C. So, it seems I am connecting my HDMI display to the Mac via an Acer 7 in 1 USB-C hub. The hub obviously must be Thunderbolt-compatible as everything that is connected to the hub functions as it should. The display works fine, it just doesn't give me the extended monitor options Apple says I have.

Thanks for your help with this issue.

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Answer 8

Apr 24, 2024 10:24 AM in response to Jimm4448

An Acer 7-in-1 USB Hub is NOT a genuine ThunderBolt Hub, which must meet higher standards to be marketed as a ThunderBolt Hub. It sounds like a very nice USB-C Hub.

if you wish to connect ONE display to that USB-C Hub, it will work fine.

If your Mac has an HDMI port, just connect an HDMI cable directly to the display. That will leave the Hub free to connect a different display.

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