Questions & Answers for LG UltraFine 4K Display

You can buy 2,3, or 4 and use them in tandem. They do not daisy chain though.

The LG 4K display does not have a DisplayPort output to support daisy chaining.

The LG 4K is a USB-C display (USB-C with DisplayPort alt mode, using DisplayPort 1.2 (4 lanes), and USB 2.0).

I don't know if macOS supports DisplayPort MST (for daisy chaining displays using DisplayPort). The MacBook Pro supports DisplayPort 1.2 which can't support more than one 4K 60 Hz display anyway.

Each side of the MacBook Pro (left side and right side) can support two displays. The MacBook Pro 15 inch allows up to four 4K displays. The MacBook Pro 13 inch allows two 4K displays.

Thunderbolt 3 can support two 4K 60 Hz displays from a single port using Thunderbolt display daisy chaining, a Thunderbolt 3 to Dual DisplayPort or HDMI 2.0 adapter, or a Thunderbolt 3 dock. However, I am unaware of any Thunderbolt 3 product that has more than one USB-C port with DisplayPort alt mode (required for USB-C displays like the LG 4K).

It might be possible to use an LG 4K with DisplayPort only (no USB) by using a USB-C to DisplayPort cable, but then any functions of the display that require USB will not be usable (audio, brightness control, USB hub). Brightness control may be possible using an app that uses DDC/CI.

To get two ports supporting USB-C with DisplayPort alt mode from a single Thunderbolt 3 port (so you can use the other 3 ports for other stuff), you need the following:
1) two Sunix UPD2018 or two Delock 89582 (PCIe USB 3.1 gen 2 host controller with USB-C DisplayPort alt mode port).
2) one Thunderbolt 3 PCIe expansion box with two or more slots such as the Sonnet Echo Express SE III, or two Thunderbolt 3 PCIe expansion boxes each with one slot such as the Sonnet Echo Express SEL (Thunderbolt 3 Edition).
3) one Thunderbolt 3 to Dual DisplayPort adapter such as the one made by Sonnet (not all Thunderbolt 3 products are Mac compatible so check the manufacturer's specs).

• Answered by Joseph V from Fort Langley
• 25/02/2018
• Flag as inappropriate Answer (I have the latest MacBook Pro - Can I buy two and use them in tandem as a dual monitor set? Do the monitors daisy chain?)

The best method that I have for turning OFF this LG display, and the Apple Thunderbolt/Apple Cinema Displays, is by setting up a "Hot Corner" where you move the mouse into an assigned corner of the monitor to initiate putting the display to sleep.


Go to:

~System Preferences
~Mission Control
~Hot Corners... (Bottom left of Mission Control menu)

...then select the corner that you would like to have as the assigned Hot Corner, open the Drop Down Menu, and select "Put Display to Sleep" and the display will go into Sleep/Standby while still supplying power to your MacBook Pro.

• Answered by Scott K from Parkland
• 13/11/2017
• Flag as inappropriate Answer (How to Turn Off LG monitor but keep charging my MacBook Pro ?)

No, the MacBook (Retina, 12-inch, Early 2016) only has one USB-C port supporting one 4K 60Hz display.

If you used Windows 10, then it may be possible to use two 4K 30 Hz displays with a MST hub but it would be difficult/expensive to get MST to work with USB-C displays such as the LG UltraFine 4K Display that won't work with a simple DisplayPort to USB-C cable (you would need to add DisplayPort to USB-C converters that include USB, such as the Sunix UPD2018 or GC-ALPINE RIDGE but the USB functions of the display such as audio, camera, brightness control, etc. would not work without a PCIe connection to your laptop).

macOS doesn't support MST because reasons (Apple). In macOS, MST works for some early 4K displays that use a separate stream for the left and right half of the display, but MST in macOS does not support multiple separate displays.

• Answered by Joseph V from Fort Langley
• 19/04/2018
• Flag as inappropriate Answer (Can I use 2 of these displays with a 12” MacBook? Either as 3 total displays or just the 2 external displays? Thanks!)

As far as I can tell, it is not. I have a mid-2015 15" macbook pro with retina display, 2.8 GHz Intel Core i7 processor, 16 gb of ram and Intel Iris Pro 1536 MB graphics card.

I've tried it with TB 3 to TB 2 convertor and an HDMI cable, a USB-C to mini DisplayPort convertor and mini DisplayPort cable, and USB-C to 4k HDMI convertor with HDMI cable / port as well, all with no luck. The mac does connect to an old TV using the HDMI cord, so I don't think it's an issue with the mac. The plan from here is to call LG support and find out if there's ANYTHING I can do that will allow me to use the monitor with the mac. Otherwise, I sure hope they'll take it back at apple, since my company bought it and I've already discarded the box.

I'll update this answer if I find any combination that works.

• Answered by Emily J from Fort Collins
• 11/12/2016
• Flag as inappropriate Answer (Is this display compatible with the previous generation of Retina MacBook Pros?)

I was just in the Apple Store and they now use the LG displays with the Mini and MacPro. I didnt check the adapter and port used.

• Answered by James V from Pikesville
• 17/03/2017
• Flag as inappropriate Answer (Does the LG Ultrafine 4k Display work with a Mac Mini?)

Did not work for me. Neither did the Thunderbolt 3 to AV multiport adapter.

• Answered by Dan U from Midland
• 11/12/2016
• Flag as inappropriate Answer (Can this display be connected to a MAC Pro (late 2013) with some sort of thunderbolt 2 to thunderbolt 3 adapter?)