Using an LG 31MU97Z display with a Mac Pro late 2013

LG is confused when they refer to that as a ThunderBolt display.

It has mini DisplayPort, and a full-size DisplayPort, and includes a Mini Displayport to DisplayPort cable in the box. It does not have any hope of working on a ThunderBolt Cable. Someone at LG knew enough to take pictures of it with the dark cylinder Mac Pro.

This article spells out what is supported. It appear by my reading that only a lower resolution (3840 by 2160) would be supported at 60 Hz using the display's SST:

Use 4K displays and Ultra HD TVs with your Mac - Apple Support

.

You can contact LG but I think that the 2013 MP will support

• DisplayPort (PC) 4096 x 2160 @60
• DisplayPort (HDMI ) 4096 x 2160 @24
• Above from:

http://www.lg.com/us/commercial/21-9-ultrawide-monitors/lg-31MU97Z-Bhttp://www.lg.com/us/commercial/21-9-ultrawide-monitors/lg-31MU97Z-B

But display port listed for both is strange.

Also, the above does not list Thunderbolt ports in the Mac compatible ports in the overview.

I have a mid 2015 15" Retina Macbook Pro with R370x and I've only been able to get it working using the included display port cable. When I use the Apple thunderbolt cable the display flashes on and off intermittently.

Hi guys,

I wanna share my experience with you.

I have a Mac Pro 5,1 mid-2010 Mac Pro 5,1 mid-2010 3,33GHz 6-core Westmere.

I first upgraded my AMD HD 5870 1GB graphic card to an AMD R9 280X 3GB flashed with perfect results with my Apple HD Cinema Display 30".

I bought a beautiful LG 31" 4K 31MU97z-B which was not compatible with my AMD R9 280X 3GB 😟, neither under 10.10.5 nor 10.11.3.

I then bought aNVIDIA GTX 980 Ti 6GB atMacVidCards and everything runs now smoothly and perfectly !

That card is also 5K compatible with 2 cables, so it's very good news 🙂

Hope that helps !

Guillaume Gaudé

I purchased the 31MU97Z thunderbolt Monitor and am using it with my late 2013 trashcan mac. It works okay, but it does have some limitations and peculiarities. Having said that, the images are wonderful. thunderbolt connectivity is okay, but sometimes on wake, the monitor has to be "re-detected" by the current OS (10.11.3), which is a much improved experience with 4k over 10.11.2. LG has sadly discontinued this product, making only the display port version available. Connectivity wise, you won't be able to daisy chain another monitor behind this one using the TB port, but that's an apple limitation, not an LG issue. All in all, if you can find one of these at a good price, you won't be disappointed.

I recently purchased an LG 31MU97Z monitor and wish to connect it to a Windows 10 PC and a Mac Pro

Mac Pro

Windows 10 16GB RAM, i5 system with a Radeon R9 380 4GB graphics card.

Both of these systems are able to run the monitor at its full DCI 4K resolution (4096x2160px) at 60Hz with the supplied LG cable. Unfortunately LG only supply one mDP to DP Real 4kx2k cable with the monitor (they provide a HDMI cable and a USB3 cable but neither of these are able to support full resolution at 60Hz).

I have tried to connect my Mac Pro to the monitor via one of the monitors two Thunderbolt ports but neither of the two ports on the monitor works even if nothing else at all is plugged into any of the other Thunderbolt ports on the Mac Pro! This should work but the screen keeps flickering on and off randomly! I can only conclude that OS X 10.11.3 (El Capitan) does not fully support this monitor, despite the two thunderbolt ports on the monitor.

When the provided LG mDP/DP cable is used the monitor works fine at full res/60Hz. The monitor is Gorgeous to use by the way!

I have tried to source another mDP/DP cable but my various attempts have all failed to find a supplier that provides a true equivalent to the LG cable. Startech.com have been very helpful and although their own cable does not work at all with this monitor, their tech support are trying to source a second cable from LG for me. I'll update you if this is successful!

In the mean time, I guess we wait and hope Apple will fully support this monitor in the next OS update so that the thunderbolt ports on the monitor can be used with a standard TB cable...

At the moment, I'm running my Mac Pro using a HDMI cable at 24Hz and the Win10 system with the LG Real 4kx2k mDP/DP cable at 60Hz until I can get another cable to run my Mac Pro at full res/60Hz as well.

If anyone has a solution for this or knows where to purchase genuine LG cables in the UK or where they can be shipped to the UK please do let me know!

Many Thanks

Mini DisplayPort to DisplayPort is a simple re-wire, not a conversion. These cables are available in the US in any length for under US$10, such as these:

http://www.monoprice.com/category?c_id=102&cp_id=10246&cs_id=1024606

Resellers are showing the same or similar cables at amazon and various electronic distributors.

It appears that the "premium" cables are rated for DisplayPort 1.2.

I've no issues at all connecting via thunderbolt cable to my Mac. I suggest trying another thunderbolt cable. Since my monitor is about 16 feet from my mac, I use a corning optical thunderbolt cable. The performance is great, and 10.11.3 absolutely supports this monitor. From what you're describing, I'd say your thunderbolt cable isn't up to the task.

Good luck!

Not all Display port cables work! Even those that are sold as fully DisplayPort 1.2 compliant. Why I do not know but I've tried a number of DisplayPort 1.2 leads now and none of these work other than the supplied cable with the monitor!

Has anyone else had experience of connections with this monitor? With whatever cables you have used? I'd like to build up a picture of what works and what doesn't.

Cyou post the spec of your mac Steve, that you have connected via thunderbolt cable?

Hi MacBoostFR, can you explain why your AMD R9 280X 3GB graphics card in your Mac Pro didn't support the LG 31MU97Z monitor please? A 3GB R9 card should have been fine I'd have thought for running this monitor? I'm using dual AMD R9 380 2GB cards however when I look in the system info Graphics section, only one of the cards is running the monitor and when a second monitor is connected (a 22inch Eizo monitor) this is connected to the same graphics card. Why the two monitors don't run on separate graphics cards I don't know. This is the case even if the two monitors are connected on different buses (e.g. Bus 0 and Bus 2 with nothing else connected to the thunderbolt ports).

Does anyone know the minimum spec graphics card for running this monitor at full res / 60Hz?