Dell U4919DW / MacBook pro 5k issue

Apple enabled single cable greater than 4096 width support in Big Sur for Intel Kabylake and Coffee Lake CPUs when the display has an EDID with a timing that has a width greater than 4096. Apple did not make the fix for Skylake CPUs so it won't work with your 2016 MacBook Pro. But it should work for the newer Macs.

https://forums.macrumors.com/threads/intel-graphics-and-5120x1440-testing-in-big-sur.2244174/

Are they thunderbolt 3 cables or USB-C cables?

Connect directly to MacBook Pro Thunderbolt port (no USB-C dock) using USB-C to DisplayPort cable?

Display set to DisplayPort 1.2?

Have you tried Display Port cable? Or still with HDMI? HDMI doesn't handle high resolutions well. I have posted extensively about this. Big Sur its not a fix.

Your senior advisor should be demoted to junior intern. Clearly he/she just wanted to throw some terms at you and hope you would give up.

Let us look back what we have known:

1, Mac with iGPU cannot drive this monitor in macOS at 5120x1440. That is why people are discussing here.

2, Mac with iGPU can drive this monitor in Windows at 5120x1440. I tested this at page 5.

3, Macbook Pro with dedicated GPU can drive this monitor in macOS at 5120x1440. JimmyWillis at page 6.

From 1 and 2, we know it is not a Dell problem nor Apple hardware, because it works in Windows. From 3 we know it is a Mac with iGPU problem because dedicated GPU work in macOS.

@Design4Paragon

I can confirm following:

1, Mac with iGPU cannot drive this monitor in macOS at 5120x1440. That is why people are discussing here.

3, Macbook Pro with dedicated GPU can drive this monitor in macOS at 5120x1440. JimmyWillis at page 6.

We tried this out here at the office with a Macbook Pro 13" 2018 and an older Macbook Pro 15". The 15" works beautifully directly plug-and-play without any change settings. Impossible to get the 13" to get the full resolution in MacOS.

Hi Don,

What I did was set it up as 2 monitors, but then enabled extended desktop, so it actually acts as a single monitor.

And truth be told, I am actually liking it more this way. First, it works perfectly with Magnet (A kind of manager I use when I have many windows open at the same time). More importantly though, I works really well with Skype like this when I have to share my screen via skype to clients.

When sharing my ultra-wide screen to clients who are on 16:9, what they ended up seeing was a long skinny view of my monitor that was impossible to read. Now by sharing 1 of the, lets call them "virtual" monitors via Skype, they can see my screen properly. This is important for me because I depend on Skype and other screen sharing methods to demonstrate our software to potential clients.

As for color differences, I set the color profile to the same for both "screens" and it works perfectly - no color difference at all.

Anyway I agree with you that it SHOULD WORK because its what Apple and Dell promise, but even if they did release a software update now, I might just stay with my current arrangement anyway.

Regardless of this: This monitor is freakin' gorgeous, and the Mac Mini is performing really well. The combo is super elegant, runs very cool, and really cleans up my desk. I highly recommend this combo even with the glitch as the world around is convenient in my opinion.

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. 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.

I am using the bundled USB-C cable and a DP to USB-C. When I enabled the PBP it automatically gave me the highest resolution. I have it set to Default for Display, the scaled is only checked to show the resolution.

I tried to speak to Apple but they gave the usual runaround of trying to reset SMC etc. When i mentioned that the display worked just fine when using Boot camp to Windows he said check with Dell that it is not a Windows compatible display only and it works with the MAC. Sometimes they can be so inflexible.

If you read the many posts here, the Trend that emerges is that Macs with a discrete graphics chip and the latest updates CAN be set up to address the full resolution of that display using one DisplayPort, and Macs that have only Integrated Graphics do not seem to be able to do that, although their specs suggest they should be able to.

Users have used the two display adapters work-around to light up the display as two halves, then combine them back into an Extended Desktop.

darenjacobs wrote:

Why does a 2018 MBP 15" drive the monitor, properly, i.e. gets 5120*1440 resolution, but the 2018 MBP 13" does not?

The 15-in is using the Discrete Graphics processor to drive the display.

The 13-in is using Integrated Intel graphics processor.

JeanLuc7 wrote:

"the Macbook Pro 2018 just can't do it."

The sad news is: it can do - but only with WIndows 10 and Bootcamp. It is just a matter of the graphics driver. With macOS, we are still stuck with the Picture-by-Picture mode and two virtual displays with 2560x1440 as a workaround.

I'm pretty sure this could be fixed if Apple wanted to. There is probably not enough demand for their Devs to take action.

Follow along:

There was a post at:

https://discussions.apple.com/thread/8641919?answerId=251185930022#251185930022

saying there was no override for the LG 49BL95.

I replied with:

https://discussions.apple.com/thread/8641919?answerId=251772844022#251772844022

saying that now there is a new override in 10.15.2 for the LG 49BL95 that might fix the problem.

The reply after that said it works for the LG 49BL95.

There was a reply to that at:

https://discussions.apple.com/thread/8641919?answerId=251773068022#251773068022

saying it didn't work with the Dell U4919DW.

I replied with:

https://discussions.apple.com/thread/8641919?answerId=251777696022#251777696022

saying that to make it work for the Dell, a copy of the override that was made for the LG has to be created for the Dell.

More info at:

https://gist.github.com/joevt/32e5efffe3459958759fb702579b9529

Your HDMI adapter (using a Parade Technologies ps176 I think) is only using two lanes of DisplayPort 1.2 so it can't do more than 4K@30Hz or 2560x1440@60Hz. Is it the older version of the Apple USB-C Digital AV Multiport Adapter or the newer one or a different HDMI adapter? For the Apple adapters, the model number is printed on the adapter.

https://forums.macrumors.com/threads/3rd-generation-ipad-pro-can-support-simultaneous-4k-60-hz-and-usb-3-0.2193083/

https://support.apple.com/en-us/HT207806

The EDID for your HDMI port is the same as the one from jizmodo except yours is from HDMI port #1 and his was from HDMI port #2. Interesting that they gave have different product IDs even though they don't have any other differences besides the port number.

So far we have 3 product IDs:

a107 = HDMI port #1

a109 = HDMI port #2

a10f = USB-C

I wonder if there are more for this display?

Interesting that the Intel Graphic Control panel allowed the 5120 x 1440 @ 45Hz mode.

I wonder if there's DisplayID info stored outside of the EDID? Accessible using DDC?

I believe source code for Intel graphics drivers exists in Linux. I wonder what it says about maximum width? Has the display been tested in Linux?

The work-around is to create an override that sets DisplayPixelDimensions manually or using SwitchResX, similar to the file in /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-1e6d/DisplayProductID-9e7b for Catalina.

The following script lists all overrides that use that property:

for thefile in $(grep --include 'Display*' -l -r DisplayPixelDimensions /System/Library/Displays/Contents/Resources/Overrides/ ); do
	printf "%s  " "$thefile"
	eval $(plutil -p $thefile | grep DisplayPixelDimensions | sed -E 's/.*0x(.{8})(.{8})}/echo $((0x\1))x$((0x\2))/')
done

The work-around doesn't work for Intel graphics because macOS Intel graphics drivers do not support resolutions wider than 4096. Macs in the future that use Ice Lake (10th gen Core CPU with gen 11 graphics) will probably not have that limit.