LG’s new 27-inch UltraFine display that outputs a 5120 x 2880 5K signal over USB-C DisplayPort works with Mac and iPad Pro, but resolution is limited to 4K on 2018 iPad Pro.

The new monitor (model number 27MD5KL-B) went on sale yesterday.

It supports 5K resolution when connected to a Mac notebook, but although it includes USB 3.1 Type-C connection allowing it to be plugged into that USB-C port on your iPad Pro, an Apple support document has now clarified that such a setup is limited to a 4K resolution of 3840 x 2160 pixels at 60Hz.

In order to take advantage of full 5K resolution, you must connect your UltraFine 5K external monitor to one of the following supported Mac computer models:

  • MacBook Pro (2016 or newer)
  • MacBook Air (2018 or newer)
  • iMac (2017 or newer)
  • iMac Pro (all models)
  • Mac mini (2018 or newer)

Another potential deal-breaker: MacBook Pro is unable to drive two UltraFine 5K Displays at full resolution (you can use two displays at 4K each). That’s odd given the previous model could be used in dual setups at full 5K resolution. In order for this to work, Apple explains, you need to plug one display into a Thunderbolt 3 (USB-C) port on the left side of your MacBook Pro and the other display into a Thunderbolt 3 (USB-C) port on the right side.

iMac Pro supports two LG UltraFine 5K displays configured as dual-link SST 5120×2880 10bpc at 60Hz while Mac mini, MacBook Air and iMac support one LG UltraFine 5K Display.

Other supported resolution are as follows:

  • 3840 x 2160 at 60Hz
    • MacBook introduced in 2015 or later.
    • Macs with Thunderbolt 2 via the Thunderbolt 3 to Thunderbolt 2 adapter.
    • iPad Pro with USB-C.
  • 3840 x 1800 at 60Hz
    • Mac mini introduced in 2014, preferably using macOS 10.12.4 or later.

Aside from the same 5K panel like in the previous 5K UltraFine Display, LG’s new monitor has aP3 wide color gamut, 500 nits of brightness, stereo speakers, camera and microphone.

It connects to your iPad’s USB-C port or your Mac’s Thunderbolt 3 port using a single cable (USB-C and Thunderbolt 3 have the same reversible connector). The USB-C port used for connecting the display to a computer delivers up to 94W of charging power to the host device, meaning it will charge the 15-inch MacBook Pro (it requires an 87W adapter to recharge).

Thunderbolt 3 embeds the USB-C protocol, but USB-C itself does not support Thunderbolt 3 out of the box, As a result, only external displays with USB-C connectivity can be plugged into the new iPad Pro’s USB-C port, not Thunderbolt ones.

As Apple itself acknowledges:

You can use the included Thunderbolt 3 (USB-C) cable to connect your MacBook Pro or MacBook Air or use the included USB-C cable to connect your MacBook or iPad Pro.

The LG monitor has deep macOS support allowing you to control the volume and brightness without the need for physical buttons on the display.

It’s available via Apple’s online store in exchange for $1,300 a pop.