Caveats included —

New USB-C dock triples M1 Mac external monitor support, Anker says

Limiting 4K to 30 Hz will be a deal-breaker for some.

Anker 563 USB-C dock

If you have an M1-based Mac, Apple says you're limited to just one external monitor. But Anker, which makes power banks, chargers, docks, and other accessories, this week released a dock that it says will boost your M1 Mac's max monitor count to three.

The $250 Anker 563 USB-C docking station, spotted by MacRumors, connects to a USB-C port on your computer (which doesn't have to be a Mac) and can also charge a laptop at up to 100 W. Of course, you'll also need to plug in the dock's 180 W power adapter. Once connected, the dock adds the following ports to your setup:

  • 2x HDMI (version not specified)
  • 1x USB-C (3.1 Gen 1): charges devices at up to 30 W
  • 1x USB-A (3.1 Gen 1): charges devices at up to 7.5 W
  • 2x USB-A (2.0)
  • 1x 3.5 mm headphone jack
  • 1x Ethernet
Port selection.
Enlarge / Port selection.

You'll need the two HDMI ports and DisplayPort to add three monitors to an M1 MacBook. There are some notable limitations, though.

If you were hoping to use a trio of 4K displays, you're out of luck. The dock can only support one 4K monitor at a time, and the output will be limited to a 30 Hz refresh rate. Most general-use monitors and TVs run at 60 Hz, and monitors can reach up to 360 Hz. 4K monitors will even hit 240 Hz this year. Running 4K at 30 Hz may be fine for watching movies, but for fast-paced action, things may not appear as smooth to keen eyes used to 60 Hz and beyond.

If you add a second external monitor via the Anker 563, a 4K screen will still run at 30 Hz via HDMI, while the DisplayPort will support up to 2560×1440 resolution at 60 Hz.

There are more disappointing caveats when looking at a tri-monitor setup. The 4K monitor will run at 30 Hz, but you can no longer use another monitor at 2560×1440. Instead, the additional two monitors are limited to 2048×1152 resolution and 60 Hz refresh rates. If the display doesn't support 2048×1152, Anker says the monitor will default to 1920×1080.

You also have to download DisplayLink software, and you must be running macOS10.14 or Windows 7 or later.

Apple says that "using docks or daisy-chaining devices doesn't increase the number of displays you can connect" to an M1 Mac, so don't be surprised if there are hiccups during operation.

Anker isn't alone in trying to do what Apple says can't be done, as noted by The Verge. Hyper, for example, offers options for adding two 4K monitors to an M1 MacBook, one at 30 Hz and one at 60 Hz. That list includes a $200 hub with a similar port selection to the Anker 563 and a two-year limited warranty (the Anker dock gives 18 months). It works via DisplayPort Alt Mode, so you don't need a DisplayLink driver, but it still requires the pesky Hyper app.

Plugable offers docking solutions that claim to work with M1 Macs for a similar price to the Anker dock, and they also limit 4K to 30 Hz.

Some docks have even more limitations when it comes to the M1, though. CalDigit notes that for its dock, "users cannot extend their desktop over two displays and will be limited to either dual 'Mirrored' displays or 1 external display depending on the dock."

Alternatively, and for several hundred dollars more, you could buy a new MacBook and upgrade to an M1 Pro, M1 Max, or M1 Ultra processor. Depending on the device, those chips can support from two to five external displays, Apple says.

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