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Dell U4919DW / MacBook pro 5k issue

Hi,


I have just purchased the Dell U4919DW monitor to use with my early 2018 MacBook Pro 13", but unfortunately I cannot choose full resolution 5120x1440 in the settings, max is 3840x1080. I have tried the app SwitchResX to manually set the 5k resolution without luck, only scaled.


From this link I read about my MacBook before purchasing the screen that:

"this model supports a maximum resolution up to 4096x2304 at 60 Hz at millions of colors on two external displays or a single external display at a maximum resolution up to 5120x2880 at 60 Hz at over a billion colors via Thunderbolt 3 (USB-C)."

MacBook Pro "Core i5" 3.1 13" Touch/Mid-2017 Specs (Mid-2017 13" (Touch Bar), MPXV2LL/A*, MacBookPro14,2, A1706, 3163): …


My MacBook Pro has 4 USB-C ports, I'm using the left ones which operate at full speed (right ones are reduced).


Why can't I get full 5k resolution? Is it an issue with the MacBook, the connection, the screen or perhaps an iOS issue?


Additional links with information on the screen:

https://www.dell.com/support/article/dk/da/dkdhs1/sln314416/dell-u4919dw-system- requirements-and-supported-configuration…

https://www.dell.com/support/article/us/en/19/sln314339/dell-u4919dw-monitor-usa ge-and-troubleshooting-guide?lang=en#Usi…

https://www.dell.com/en-us/shop/dell-ultrasharp-49-curved-monitor-u4919dw/apd/21 0-arnw/monitors-monitor-accessories

MacBook Pro TouchBar and Touch ID, iOS 12.1

Posted on Nov 21, 2018 11:09 PM

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682 replies

Dec 21, 2019 11:07 AM in response to kanonendk

Solved... with a little more spending at the Apple store.


I started with:


  • Samsung CRG90 - 49 Inch Ultrawide (5120 x 1440)
  • 13 inch Macbook Pro (2019)


and needed to buy...



To get it working.



I can't take credit as I followed this guy - https://blog.comdivision.com/blog/2019/05/using-the-philips-499p9h-with-a-13-macbook-pro-and-a-blackmagic-egpu-pro


  • You don't need to get the more expensive eGPU PRO, just the standard will do.
  • I needed a Moshi display port cable as the Samsung doesn't have any thunderbolt ports.
  • I assume any Macbooks from 2017 will work


The eGPU and SwitchResX are essential to get this working. I tried without both. Maybe, the eGPU would be essential anyway to reduce the load on the small 13 inch MacBooks internal cards.


It is a little disappointing, but maybe not unsurprising from Apple, to have to buy this additional kit. It was an struggle to overcome my pride, more than anything, to go ahead with it.


But in the end, it is very impressive, and I love it - I may have a little bias following the work gone in to it haha!


I have no idea if this can be done any other way, or with any other graphics cards.


This thread helped as it lead me to believe there was no other way.


I hope this helps someone!



Jan 14, 2019 2:35 PM in response to Mark from 2Much

So I had my final conversation with my Senior Advisor today. Here is what I emailed him last week, in preparation for today's conversation...


I look forward to hearing from you this coming Monday. I had one more thing to ask you during that discussion. Here are a few thoughts...

    1. The Dell monitor is a 5K, SST monitor.
    2. Apple Engineering says that 5K displays are only supported for MST monitors.
    3. Therefore the Dell monitor will not be supported at 5K, and the scaling that I observe is expected behavior.
    4. However, I read at this page that the 27" LG UltraFine 5K monitor is supported by the 2016 MacBook Pro and later.
    5. I emailed LG support whether that specific monitor was an SST or an MST monitor. They replied that it was an SST monitor.
    6. Which means that premise #2 above is not always true.
    7. Which leads to the next logical question: What makes the LG 27" SST monitor compatible with the 2016 MacBook Pro and the Dell U4919DW not compatible?


He responded that an exception was probably made for the LG monitor to override the SST/MST limitation and that basically I would need to go to Apple.com/feedback if I wanted Apple to apply that same exception to this monitor. In other words, he conceded the point that SST is not always a limitation. I hope one of the other 32:9 displays is compatible.

Nov 27, 2018 8:43 AM in response to Grant Bennet-Alder

According to this website, every connection type should produce full resolution with the exception of HDMI 1.4...


User uploaded file


Odd that nothing is working. Someone marked this thread as "Resolved." Since it hasn't been resolved, we might benefit from "Unresolving" it. Might generate more discussion from the community.


Also curious to know whether it is an Apple problem or a Dell problem. I talked to both and they said that it "should" work. Has anyone called Apple or Dell support and had them walk through step-by-step?

Nov 29, 2018 5:09 AM in response to MrADeveci

If you have the most recent Mac mini, it should have a maximum resolution of 5120x2880...

User uploaded file

I found that right on Apple's website https://www.apple.com/mac-mini/specs/.


So he was wrong in stating that the maximum resolution is 4096x2160 (unless you have a different model). I also am unsure what he means by stating that the resolution will "meet halfway."


jkastan's experiment above would seem to indicate that it's a software issue rather than a hardware issue. And my suspicion is that it's a Dell issue instead of an Apple issue. I'd be interested to see if the issue could be moved higher up to a "Senior Technician" at Dell.

Nov 29, 2018 11:35 AM in response to MrADeveci

Looks like Dell doesn't want anyone to know that there are compatibility issues with the Mac. Someone posted in the questions section of the U4919DW and said, "Would this monitor work with a 2018 MacBook Pro (13")? 2) Does anybody have specs for this monitor without the stand? Thanks for the feedback."


I responded, "It's not entirely clear at this point. According to both Dell and Apple, the monitor "should" work. However, there are several individuals who are finding that in practice, the monitor scales the resolution to 3840x1080. Hopefully a solution can be provided soon. See this thread: https://discussions.apple.com/thread/8641919"


I received an email stating, "Your answer has been moderated." See below...


User uploaded file User uploaded file

Jun 12, 2019 3:37 PM in response to kanonendk

I also just got my Dell U4919 DW and having the same issues as described here.


First of all, if you are using the cables provided with the display you should absolutely be able to get the full resolution on supported Mac's (e.g. I've a 2016 MBP 13"). I validated this by installing Windows 10 in BootCamp and I was able to select the full 5120*1440. Looks like Windows somehow get the full resolution from the display channel or does have a plug & play driver in place - idk. macOS Catalina beta 1 also doesn't seem to fix the issue.




I did some analysis on that issue and probably found the root cause:


Displays communicate with the client by sending an EDID (Extended Display Identification Data). This 128 byte long data contains all informations about the display, like manufacturer, serial number, supported "standard" resolution and the native resolution.




The EDID of the U4919DW (and likely all other displays with resolutions greater than 4096 pixels ) contains 3840*1080 as the native resolution. Thats not a fault by the manufacturer but a limit of the EDID standard. The data field which contains the native resolution is 8 bytes in length for native high and width of the display. Therefore there are 4 bytes for high and 4 bytes for width which leaves us with a max value of 4096 (8^4).




Since apple already supports a variety of displays with resolutions higher than 4096, there must already be a technical solution for these displays, right?


It turns out, there is - its called "display overrides". 


Display overrides are placed in /System/Library/Displays/Contents/Resources/Overrides (SIP Protected Folder)




With way over 300 display override files, Apple actively using this technology to modify EDID's to get "problematic" displays to work correctly.


Just overriding the EDID (which would be easy since those files just contains the VendorID, ProductID and the "custom" EDID) won't work in this case because the EDID data field is to small for the value. 




Apple seems to have an additional technology for this case called "overlay" which are defined in .mtdd files which are also located at the path mentioned above. It looks like they even use .mtdd files for the LG 5k Ultrafine displays. 




Unfortunately I was not able to find any documentation for the mtdd overlay value (seems to be 384 bytes long).


Therefore we now know the root cause and the theoretical solution.




Maybe there is someone out there which knows how the overlay value in the mtdd files is calculated?


I also did open a Radar bug report providing vendor, displayid and the EDID of my U4919DW. 


As a fix might be implemented very easy, hopefully Apple will implement this soon.

Dec 28, 2019 9:30 AM in response to joevt

The Color Menu says RGB for both settings. But I am able to change it manually to YPbPr.


I am able to create, save and use the custom resolution I created.


The output via a budget USB-C to HDMI Adapter is attached like the others before. The problem I have with HDMI is the maximum resolution of 1920x540 or 1920x1080. Both times with 59,88 Hertz. And the monitor is quite pink via adapter.

When using the adapter with the windows boot it's working quite fine even if the refresh rate is limited to 30Hertz.


Nov 24, 2018 9:52 AM in response to kanonendk

There is no requirement to turn off the internal display. The hardware for the Internal and the Hardware for the External are completely separate.


The fundamental problem is likely the adapter you are using. Most adapters will not work for this case at full resolution. This one appears to do the job, and is cheaper than most that almost work:



Moshi USB-C to DisplayPort Cable --$49.95


.

Nov 29, 2018 11:55 AM in response to MrADeveci

Has anyone tried a dual cable setup? This is an old article, but it got me thinking that maybe in order to drive the Dell 5K screen on Mac OS, it needs to be fed by 2 cables? My MPB 13" only has 2 USB-C ports, so if that is the case I will need to figure out a port solution. See also https://support.apple.com/en-us/HT206587.


I only have 1 Thunderbolt 3 to Displayport cable but thought I would toss out the thought to the group...

Dec 4, 2018 10:43 PM in response to marino389

So, Dell just emailed me this..... which basically means they are washing their hands of this issue and blaming Apple.


Dear Ahmet Deveci,


This is Yvette from Dell Technical Email Support making a follow-up on Service Request # **********.


As we have further review the issue and based on the link provided https://discussions.apple.com/thread/8641919?page=4, it is a compatibility issue, Dell monitor is provided as is, we would recommend to please contact Apple support if there is an update needed as it was confirmed that same issue is happening under mac mini and the macbook pro from the thread.I look forward to your response at your earliest convenience. Should you have any further queries, please do not hesitate to contact me.

Kind Regards,

Yvette Macambac
Dell Rep ID: 741093
UKI/SA Relationship Client Mailbox Team

Jan 3, 2019 2:24 PM in response to MrADeveci

I received my scheduled callback today from my Senior Advisor. He submitted a ticket to Engineering, and their response was that the Mac doesn't support that resolution. He then looked up the specifications and discovered (as we all have already noted) that the MacBook supports an even higher resolution (5120 x 2880). He then reached back out to Engineering to inform them that they were incorrect, but he hasn't had a response yet. He is scheduling another callback for this Sunday.


I am wondering if the Mac is having trouble cutting the 2880 number in half. In other words, is it all or nothing with the 5120 x 2880? Perhaps it sees that it cannot do the "full 5K" and therefore scales it down to the next resolution.


If my theory is correct, that would mean that unless resolved, the Mac would never work with the other 32:9 5K monitors that are being released (I hope this isn't the case). Philips is releasing their 32:9 5K monitor soon. I've read that it should be released end of January or beginning of February. Model is 499P9H.


Has anyone had any USB-A trouble like I referenced in my earlier post? If so, I'd love to interact on that here.

Jan 7, 2019 12:12 AM in response to marino389

Hi Marino,

Tnx for the update.


What is SST and MST? In

order to achieve 4K resolution at 60Hz, most early 4K displays on the market

used Multi-Stream Transport (MST), a technology that stitches two halves of a

display together into one large surface -- also called a "tile" -- in

software. MST, supported on Thunderbolt 2 Macs, can carry a signal for two or

more monitors on a single cable, allowing for daisy chaining or hub

configurations of multiple 4K monitors. 



More recent 4K displays have

started using Single-Stream Transport (SST), eliminating the need for stitching

two halves of a display together in software. Instead, SST monitors feature

scalers that support 4K resolution at 60 Hz over a single tile. Ideally, if you

are purchasing a 4K display, you should look for one that supports SST, since

MST can cause issues with in-game menus, BIOS screens and scaling.


Apple also has a link:

https://support.apple.com/en-us/HT206587


Really don't know why MST should be used, are you connecting it over USB-C, HDMI, DP ?

On some Dell Monitors you can enable disable this.





Dell U4919DW / MacBook pro 5k issue

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