Dell U4919DW / MacBook pro 5k issue

Yes correct.

I have the 13" MacBook Pro 2018 with Touch Bar and Dell U4919DW does not work as a single display over Thunderbolt 3.

Currently I have to use the display as 2 different displays by driving it with both USB-C and HDMI (another dongle) which really is a subpar experience since it's 2 cables and window management is a pain (you can't have a window in the "middle")

It seems to be a software limitation in MacOS.

I had the issue explained here, and used “dual monitor mode” as a solution.

Then I bought an eGPU (Razer Core X) and an AMD RX580. Right out of the box the monitor worked great as intended.

Such a strange and frustrating limitation.

Thanks for the reply @zamol74,

ResXtreme can just be a temp solution, and there is nothing todo with Dell here, I installed Windows using Bootcamp and it recognize U4919DW as 5120x1440, no problem there, so Apple should provide a solution for this there is an obvious discrepancy here, as they publish their devices (at least the one I own, MBP Late 2016) should support up to 5120x2600. I suppose there are hundreds of 49' Mac users around and counting up everyday and all we are in dark atm. Shame on Apple guys, if they still did not come up with a solution yet for months.

I have the same problem (only getting 3840x1080 without a third party app, and only able to get scaled 5120x1440 - i.e. blurry, not truly 5120x1440) on a Macbook 12" Retina from 2017.

This laptop supports one external monitor 4096x2304@60hz (at the same time as the native 12" display) according to Apple's specification pages: https://support.apple.com/kb/sp757?locale=en_GB

I don't know how to reason about this. 4096x2304 is more pixels than 5120x1440. But 5120 is a wider resolution - maybe that is what causes the problem? It is true that the specification states "up to" 4096x2304. Maybe that is to be interpreted as up to 4096px on the width, and up to 2304px on the height, instead of up to 4096x2304 ( =9,437,184 ) pixels in total. 5120x1440 = 7,372,800 pixels is a lower total amount of pixels, but the greater width (5120 > 4096) is maybe the thing that isn't supported?

But then at least the people having a Mac Mini 2018 should get it to work, because the specification pages for that model says it supports up to 5120x2880@60hz. https://support.apple.com/kb/SP782?locale=en_US

So I guess it is a problem with the specific solution 5120x1440.

Have only tried with the USB-C cable coming with the Philips 499H9P monitor.

Have tested the monitor with another PC running Windows 7 and it works flawlessly (looks gorgeous). Just had to plug and play. However, the PC does have a dedicated graphics card, but no USB-C port, so I used the DP-DP cable that came with the monitor.

I did some more tests by manipulating the EDID this week.

By really messing up the EDID in a lot of ways, I was able to get the 5120x1440 in the "About my Mac" -> Displays dialog using HDMI to USB-C cable and in the "scaled" dialog. But unfortunately, the "real resolution" just was 3840x1440 (so at least the hight resolution was correct). It has some side effects with the color of the display, but I believe this can be solved once we confirmed that the macOS Intel HD Graphics driver is able to display 5120x1440.

I was not able to reproduce this with the USB-C to USB-C cable delivered by Dell, probably the driver handles USB-C to USB-C different, idk.

I'm not sure, but the HDMI to USB-C cables I got on Amazon for PBP are advertised just with 4k support. So probably only the bandwidth of the cables was the limit to "really" get the full 5120x1440.

I was not able to find any HDMI to USB-C cables which supports 5k. In theory, a HDMI to USB-C adapter which supports 5k and does not have a separate driver and does not change the EDID should also work.

Does anyone of you have such an HDMI to USB-C 5k adapter and is willing to mess around with the EDID to validate that the macOS graphics driver is at least able to display 5120x1440? If so, let me know so I can post the EDID.

I would also ask all of you to issue a bug report (https://feedbackassistant.apple.com) , so Apple becomes aware of that problem.

StewQ--

We have not heard reports of Apple support experts being very upbeat about supporting these really big displays using one interface with Intel Integrated graphics on any Mac. Your Mac mini features only Intel Integrated graphics, but it does say it supports one 5K display over ThunderBolt (which implies support over DisplayPort family as well)..

The only encouraging mutterings have been regarding Discrete graphics, or Picture-beside-Picture (PBP) using two interfaces for displays that support this feature.

¿Are you using a direct ThunderBolt connection or DisplayPort family, not a "legacy" interface like HDMI?

The terminology involved is a BIG Problem.

USB-C is the name of the Connector, ONLY. It does not in any way describe the features of the cables that plug into it.

The classic counter-example is the MacBook Charging cable, which has a USB-C connector at each end, but has no high-speed pathways at all. It reluctantly will support USB-2 (suitable for running a keyboard) because that is how it negotiates the charging Voltage with the power adapter.

Lobster_Wrangler.

as I posted already, I have a 2018 15” MacBook Pro with Radeon pro 555x graphics and am able to connect it to this monitor using the moshi usb-c to DisplayPort cable. Everything is working great at full 5120x1440 resolution. I have to confirm if I get the full 120hz refresh rate once again.

Hi there!

I just phone called Apple to ask whether this was a known issue that will be fixed when the next MacOS comes next month. Unfortunately he could neither confirm it was a known issue, nor that it will be fixed. We just had to wait and try.

But we can hope for a fix in the next MacOS. If you sign up for the Apple Beta Software Program (free and open for everyone) https://beta.apple.com/sp/betaprogram/ you are able to install the latest beta of the coming MacOS Catalina.

Can you or someone else in this thread check if the full resolution is working with the current beta? I have the beta installed, but I have not bought the screen yet because of those problems. If the beta does not work with the monitor it is possible to revert back to the stable MacOS you had.

JeanLuc7

You cannot set SwichResX to support a native 5120x1440 resolution. You have to use the Picture-by-Picture function and instal two displays with 2560x1440 side by side.

Is this the only work around? Is there no way to modify an existing driver?

Actually I explained that with my MacBook Pro and Dell 49, I had normal resolution of 5120... on macOS Mojave, and 30 minutes later after installing macOS Catalina beta with the same cable, same monitor, same MacBook, zero changes I wasn’t able to have it again.

So it is definitely something they should be able to fix :)

With a 15" MBP (and the AMD graphics chip) you should be able to run 5120x1440 OOB. At least with 10.14 Mojave, this has never been an issue with 15" models, it was related to 13" models and the new Mac mini 2018. Try SwitchResX, if you cannot find the right solution in Catalina.

zamol74 wrote:

I update my MacBook Pro 15" with Catalina and now I can choose 5120*1440 in the setting. Before, I used ResXtreme but now it's like working without the app.

But there is not a difference in quality between before with the application ResXstrem and now via the native settings.

I think it's probably using a scaled version of the resolution. Which is just horrible. Hopefully someone from Apple might just read this forum and do something about this, but I'm not holding my breath. It will probably be a while before any of this stuff is addressed if at all

joevt wrote:

Maybe you can post information to a new Mac Rumors thread, where you can attach files (AGDCDiagnose command output, screen shots from SwitchResX, a list of files in your overrides folder) that contain info that can help diagnose the problem.

I'd be happy to do that, but my question is have you or anyone else been able to get native 5120x1440 (non-scaled) resolution on a MBP 13" or Mac Mini?

Joevt,

Yes, the hardware MBP 13" w/ Intel Graphics card is capable of 5120x1440 resolution as evidenced by booting into Windows on a MBP 13". Windows can display this resolution on this laptop. This is not a hardware issue this is an OS issue, which would be nice of Apple addressed.