LG 34WK95U (UltraWide 5k monitor) and MacBook Pro 2018

I just got the same monitor. It works fine on my 2016 MacBook Pro and my 2017 MacBook Pro, but not, as you indicate, on my 2018 MacBook Pro. Your results on your 2018 MacBook Pro are better than mine. Mine just keeps flipping around and can never make a connection. It just goes to show you. You should dig deep before spending $1500, and then dig deeper. Nonetheless I am quite happy with the monitor and look forward to all the bugs being shaken out so that I can use it with my primary machine.

LG Themselves acknowledges the problem at LG 34” 21:9 UltraWide™ WUHD (5120 x 2160) Nano IPS Display | LG UK

I'm going to attach their supported connection chart which shows the various ways of connecting the monitor. Of particular interest you might want to look at the USB-C to DisplayPort Connection which supposedly works on the MacBook Pro 2018 providing full 5120x2160 @60Hz. As I read the chart it indicates that the that the connection to the monitor is the DisplayPort end (obviously as the MacBook Pro only has USB-C/ThunderBolt 3).

So the question is which USB-C DisplayPort adapter do you use. You have to be careful here because most indicate they only support 4K @60Hz max, no matter what the MacBook Pro can handle.

I looked around and I found this: https://www.amazon.com/dp/B075B1GQFP/ref=ox_ya_os_product

Its description states:

"... Plugable Thunderbolt 3 to Dual DisplayPort Display Adapter Compatible with Late 2016/2017/2018 MacBook Pro Systems (Supports Up to Two 4K 60Hz Monitors Or One 5K) ..."

The encouraging part being the "Or One 5K."

There are several adapters that offer the single 5K btw.

https://www.amazon.com/Nekteck-Certified-Thunderbolt-DisplayPort-Converter/dp/B0 6XYL72RL/ref=sr_1_2?s=electronics&ie=UTF…

https://www.amazon.com/Wavlink-Thunderbolt-DisplayPort-Adapter-Converter/dp/B07C LLX6XS/ref=sr_1_7?s=electronics&ie=UTF8&…

https://www.amazon.com/SIIG-Thunderbolt-Dual-DisplayPort-Adapter/dp/B07611SJW1/r ef=sr_1_15?s=electronics&ie=UTF8&qid=1541944261&sr=1-15&keywords=usb-c+to+displa yport+5k%4060hz

https://www.amazon.com/Sonnet-Thunderbolt-Dual-DisplayPort-Adapter/dp/B073H78ZZP /ref=pd_sbs_147_2?_encoding=UTF8&pd_rd_i…

There are also docks that provide this feature.

In the box that came with your monitor you should have received a DisplayPort <--> DisplayPort cable. So I'm going to try connecting the Thunderbolt end to my MacBook Pro to the DisplayPort of the monitor and if it works I will report back here, and on Reddit where I also saw your post.

The nice thing is that if this works, it means I can connect my 2017 and 2018 MacBook Pros to the monitor simultaneously and access them just by switching inputs on the monitor. Theoretically. Bad news is that this little puppy is $75. So you might want to wait until you find out what happens to me before dropping your $75.

LG Statement:

Good Luck!!

I have to go collude with a Russian.

To see the full 5120 x 2160, MacBook Pro users often have to bring up system preferences, and launch the Displays preference panel. Instead of choosing one of the icons for your resolution, Option-Click on the word Scaled. You should get an extended list of resolutions. Select 5120 x 2160.

See if that works.

This is my 2016 MacBook Pro and it works, nothing special, just using the cable I got with the monitor and setting the preferences through the standard Displays preference panel, with the caveat of Option-Clicking on the word scaled to set the resolution properly, as I described above.

Really?? You have the exact opposite of the problem I had. Mojave was the solution for me. Have you tried the trick some others have had success with, by hooking the factory power brick back up to one of the TB/USB-C ports and THEN connecting the TB cable to the monitor? See screenshot below I grabbed from Reddit thread last night...

The 5120 x 2160 has been an incredible productivity boost for me. Especially when you take into account Mission Control with multiple desktops.

I support a lot of desktops and networks from home and one thing I really love is being able to open multiple client workstations on my one monitor.

This guy has 2 additional monitors connected to his iMac Pro and I can now see all 3 monitors simultaneously.

Well I did test this one and it worked perfectly.

https://www.amazon.com/dp/B075B1GQFP/ref=ox_ya_os_product

Its description states:

"... Plugable Thunderbolt 3 to Dual DisplayPort Display Adapter Compatible with Late 2016/2017/2018 MacBook Pro Systems (Supports Up to Two 4K 60Hz Monitors Or One 5K) ..."

I got the full 5120 x 2160 Resolution. I used the Display Port cable that came with the monitor.

Nonetheless, the quick fix of...

- Restarting the computer with the monitor directly connected to the Thunderbolt-3 port

- Disconnecting the cable from the monitor after the keyboard lights go out

- Plugging the cable back in after the Apple logo appears

Works for me as well. No attachments, no extra power cable.

There have been reports that the current 10.14.2 beta works as well. I like the monitor so much now, I'm considering buying a 2nd.

You are absolutely 100% correct and I should have stipulated that this is at 30Hz. For my purposes which are largely typing and working on remote desktops, servers, routers, switches and code, virtual Windoze, virtual LINUX, this is fine. If I were looking for higher refresh rate I probably would have gone with a different adapter. It was an experiment for me. I installed SwitchResX to confirm as you advised:

The monitor is indeed running at 30Hz but comfortably with the resolution I wanted.

I did find, a day or so later, an adapter for the same cost that notes 5K at 60Hz:

Ableconn TBT3-DPX2 [Certified] Thunderbolt 3 to Dual DisplayPort Adapter for Mac and Windows Systems - Support Two UHD 4K 60Hz or single 5K 60Hz https://amzn.to/2Q28UQA

Still, at this point I'm happy with the standard Thunderbolt-3 cable connection:

I think all of those Thunderbolt 3 to Dual DisplayPort adapters (there's more than 20 of them) only support 5K on displays like the Dell UP2715K that use two DisplayPort 1.2 connections (they use the older Alpine Ridge Thunderbolt controller). Any dock that says they support 5K and uses Alpine Ridge Thunderbolt controller can connect a 5K display that requires two DisplayPort 1.2 connections either over a single Thunderbolt 3 connection or with two DisplayPort cables.

Moshi has a USB-C to DisplayPort cable supporting 5K (supports DisplayPort 1.4) and is bidirectional (so it could be used as a DisplayPort to USB-C cable).

https://www.apple.com/ca/shop/product/HLR62ZM/A/moshi-usb-c-to-displayport-cable

If you have a computer with Thunderbolt 3 ports that support DisplayPort 1.4 then there's a Thunderbolt 3 to Dual DisplayPort 1.4 adapter that may work (it uses the new Titan Ridge Thunderbolt controller).

https://www.globalsources.com/gsol/I/DisplayPort-adapter/p/sm/1163916845.htm#116 3916845

I wonder why the notice on the LG UK site is not on the US site?

I wonder why the Notice says the USB-C port is limited to only 4K (non-Thunderbolt) but the manual says the max resolution for USB-C is 5K 60Hz. This is where I would try the Moshi bidirectional cable - connect the USB-C end to the display.

The 15-in 2018 MacBook pro supports up to two at 5220 by 2880

USB Type-C™ is a specific feature of a product, it is not a generic description. Think of “USB Type-C” as an adjective, not as a noun.

from:

http://www.usb.org/developers/usbtypec/USB_Type-C_Language_Product_and_Packaging _Guidelines_FINAL.pdf

EXACTLY what cables/adapters are you attempting to use?

Like many home-made you tube videos, that one is also tremendous waste of pixels. Most of its information could have been condensed into a brief written article with no loss of significance, and far easier reference to pertinent facts.

Two possible take-aways that were mumbled in passing:

"Requires Discrete GPU: not supported on the [implied 13-in model] with only Integrated Graphics."

"the 2018 MacBook Pro and Mojave currently have a problem that keeps this display from working properly"

Make certain you have the latest version of Mojave (10.14.1 at this writing) and the Security Update that was issued about 6 November 2108.

Beyond that, you may need to contact the manufacturer for more support.

Yes, I am having exactly the same issues. The full 5k works sometimes after a reboot with switching to different USB-C ports back and forth (praying and swearing) for me.

It's looks like it's a known issue related to the latest MacBooks 15" in which either LG or Apple or both have to fix.

According to LG:

"...this compatibility issue is not being caused by the monitor and so is something that you would have to contact Apple about in order to receive further information. I am sorry for any inconvenience that this may cause..."

The interesting thing is that they also recommended a cable to me that says it only supports 4K @60HZ. I might try one of the cheaper cables at some point just to see if it works.

So I guess I will go report the monitor problem as a bug to Apple to see if there is any acknowledgement or the typical silence of the Gods.

------ Full LG response ------

Hi Marvin

Thank you for your response.

I have received a response back from my technical team and they have advised me that this compatibility issue is not being caused by the monitor and so is something that you would have to contact Apple about in order to receive further information. I am sorry for any inconvenience that this may cause.

In regards to your query relating to the USB-C to DisplayPort cable, this is not something that LG manufacture, however I have included a link below that will confirm the price and availability of this product.

https://www.amazon.co.uk/DisplayPort-uni-Thunderbolt-MacBook-Pixelbook/dp/B075V2 7G2R/ref=sr_1_6?s=electronics&ie=UTF8&qid=1542039399&sr=1-6&keywords=usb+c+to+d i splayport

Should you have any questions regarding LG products in the future, please do not hesitate to contact us again for assistance.

If you have any questions or queries please either call us on 0344 847*** or use our live web chat option on our website www.lg.com/uk

Kind Regards

Ryan

LG Electronics UK Help desk

Btw my Lg have type c port and orginal cable type c to type c it work 5k display .. Dont need external adapter port. Then i use mirror display and arrangement in mirror option it any i can move screen

I did also, but they finally got around to responding to me this morning. They asked for the sysdiagnose and I just supplied it. I'm also receiving the Thunderbolt to DisplayPort cable today and look forward to trying that.