Dell U4919DW / MacBook pro 5k issue

There is a report that single cable 5120x1440 works with the MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports). If the 2019 is just a minor upgrade of your 2018, then your 2018 might work in Big Sur. If you try it, report your system info and results to https://forums.macrumors.com/threads/intel-graphics-and-5120x1440-testing-in-big-sur.2244174/

I haven't tried the public beta yet. Big Sur is only in beta so things could change for release.

You don't need a DisplayPort 1.4 cable for 5120x1440 since it requires less bandwidth than 4K and Intel graphics can't do DisplayPort 1.4 anyway. The problem you had was using HDMI instead of DisplayPort.

Sorry, but you are wrong. What matters for the GPU is only the maximum pixel clock. In the DELL case, it is only half the value as with 5k - and even less than 4k. Any GPU that supports 4k should also support 5120x1440 oob. There is no hardware reason why 5120 pixels width should be a limitation.

Regarding the older Intel CPU's, you may have a look at Bootcamp installations with Windows - there, 5120x1440 works oob like a charm. It is not a hardware limitation, but one of the Apple GPU software driver.

I am using mine on Samsung CRG9 and Odyssey LC49G95T- both are 49" monitors. They were (individually, not separately) plugged in using a Display-Port (DP) from my Belkin dock and DP-DP cables supplied by Samsung. Immediately the M1 MBP recognised the 32:9 factor with 120 Hz & 200Hz refresh rates respectively.

When I accidentally used a HDMI port, the resolution dropped.

I use Switch Res X to confirm and set the monitor settings. It works comfortably on M1 MBP. 'Magnet' which is available from the Mac app store helps in positioning windows on the huge screen. Believe me, you will need some such or equivalent.

I don't have experience with the Dell4919DW, but I would expect the M1 MBP to handle it with ease.

Please keep in mind that the M1 MBP can handle only 1 external display. With a 49" display, only a rare user will want another external display.

FINALLY figured out the best workaround after struggling with this for 6 months. Whenever you extend displays when connected via USB-C, the Dell would go dark and you cannot follow or see the mouse scroller on your laptop screen. I spoke to both Apple and Dell and they know it is a known issue, but neither knew for certain how to get the handshake to reset. Sometimes I would get luck and after messing with keys, the Touch Bar would show extend or mirror, when switching into mirror, handshake works. The way to force this would be using your key shortcut to change from extend to mirror (and vice versa) - Cmd + Dim button on the left side of your Touch Bar. This will allow you to now see your settings (albeit very small) on your laptop, change resolution to 3480 x 1080 and and mirrors fine. Another temp solution I figured out prior was clicking on your airplay to a device and for some reason that also works, however, after a while may kick airplay off and you have to re-sync.

I am hopeful this issue goes away and I am able to get full resolution with the new mac mini I just ordered, if not, I will return it and wait for a graphics card that can sync with no issue. PCs have NO ISSUES as it is truly plug and play with top resolution...so this is a mac 'handshake' issue.

Hope this helps others...drove me nuts trying to work around this (Apple rep asked me to please post if I was able to figure it out).

Good luck!

Looks like the final build of 10.14.2 was released. Has anyone updated today? Any difference?

It works perfectly when connected to my iMac Pro. A 5K plus a 5K2K 2nd display. So it may not be a universal MacOS issue.

It work in MacOS Mojave Version 10.14.2, MacBook Pro (15-inch, 2018), USB type C Cable to U4919DW.

It would appear that someone needs to make a MacOS compatible driver. Or else an "override" file, similar to the one found here.

Mark, would you mind telling us how you've connected them to the mini? Thanks.

Thanks dylanks, that proves that the problem lies in Intel's drivers, just as I suspected. I think we should reach out to Intel and make them aware of this issue.

The Intel Iris may be one of the issues, but I think that there are also some other issues with the OS.

I have a AMD Radeon R9 M370X, which should support the resolution, but sadly it is not working.

Yes, please in the future read the thread! Its a problem with the 13" not the 15", we are all already aware the 15" is working fine.

I can confirm that the latest update (released today) fixed the issue. Everything is working great! So much better! I have a Mac Mini 2018.

well to the computer they are two displays. so it should work.