Dell U4919DW / MacBook pro 5k issue

That's a good question. The MBP 13" and Mac mini 2018 use Intel graphics instead of AMD graphics.

We know that Intel graphics can have a frame buffer as large as 6720x3780 to support HiDPI mode of 3360x1890. But what about the actual DisplayPort signal? Intel graphics supports DisplayPort 1.2. DisplayPort 1.2 should allow any resolution that uses less bandwidth than 17.28 Gbps (720 MHz for 8bpc, 576 MHz for 10bpc). Here's some examples:

5120x2880@60Hz (938 MHz - too much, but 45Hz is only 699 MHz 8bpc)

5120x2160@60Hz (703 MHz 8bpc - might be too close to 720 MHz 8bpc limit?)

4096x2304@60Hz (605 MHz 8bpc)

3840x2160@60Hz (533 MHz 10bpc)

5120x1440@60Hz (469 MHz 10bpc)

Can the Intel graphics support resolutions wider than 4K? Even if the total number of pixels is less than 3840x2160, such as 5120x1440?

I don't have a LCD display wider than 3840 but I do have a CRT. With a CRT, the only limit for the width is the pixel clock of the DAC. I have a USB-C to VGA adapter which can do 330 MHz but macOS limits it to 160 MHz for Intel graphics. There's a patch for that:

https://github.com/Floris497/mac-pixel-clock-patch-V2/issues/323

I was able to create a resolution of 4096x1216@48Hz (GTF timing, 327.72 MHz) which works.

Then I tried 4104x1216@48Hz (GTF timing, 328.33 MHz). macOS would not allow it, even if it does work with my CRT.

Is the limit in the macOS drivers? I checked Windows. The Intel Graphics Control Panel would not allow > 4096 width. It says "The custom resolution exceeds the maximum bandwidth capacity." even if I half the bandwidth (24 Hz which is allowed by resolutions ≤ 4096 pixels wide).

So it seems the limitation is in the Intel graphics hardware. You can't get more then 4096 wide unless you use a dual-cable display or a dual-link SST display. Seems Apple rewrote their "Use 4K displays, 5K displays, and Ultra HD TVs with your Mac" support document and removed all mention of SST, MST, and dual-cable (now it's called "Use external monitors with your Mac")

https://support.apple.com/HT202351

I suppose they may have decided to write a separate document for each computer:

https://support.apple.com/en-ca/HT208366

While it mentions 5120x2880@60Hz, it should say that it must be a dual-link SST display.

Dual-link SST (as well as SST and MST) are mentioned in:

https://support.apple.com/en-ca/HT208366

macOS does support the extended portion of the EDID (if you are referring to DisplayID extension blocks). That's how displays advertise resolutions greater than 4096 wide. It's where SwitchResX puts such custom resolutions in override files.

You can try the following command in Terminal.app to see if macOS at least tries to add the 5120x1440 mode. First, if you can, disconnect all displays except the one you are testing - it might make the output more readable. Run the following command:

log stream --predicate '(sender contains "Thunderbolt" or sender contains "Graphics" or sender contains "Display") and (not message contains "surface is not detached")' --style compact --debug --signpost

Press "Command-K" to clear the terminal window. Power off the display or change the input to one that is not connected, or disconnect the display. Wait a few seconds. Press "Command-K" again. Power on the display or change the input back or reconnect the display. Then copy the results to a text file after it has stopped scrolling.

In the log, you should see Hot_Plug, then EDID, then DPCD_Info, then it tries to validate and install all the timings and modes. You can grep for Active:\d{2,}x\d+ for all the modes that are attempted. Some of them should be the 5120x1440 resolution. It might say why it was declined. The errors I get with the 4104 resolution is "Mode with width 4104 and max 4096 rejected with multilink set to 0", "Source size is out of bounds", "because Driver_Validation".

Did you check Intel Graphics Control Panel? Does it show the 5120x1440 mode there? Can you make a custom resolution 5120x1440 50Hz? I would like to see screen shots in Windows and AGDCDiagnose output in macOS. I wonder if Windows is using MST? macOS support MST for some 4K displays. AGDCDiagnose might give a clue. HDMI doesn't have MST. If the display has an HDMI 2.0 input, then you could try that in Windows and see if it also supports 5120x1440 that way? If it does, then we can say it's working without requiring MST. Check the log stream output I mentioned in my previous post to see if you get the same errors.

We ned to apply good old logic here:

Mac mini 2018/19 works perfectly with Dell if you're booted under windows or linux via bootcamp.

OSX does not.

Hardware combination has zero issues.

OSX does.

It's making me want to weep so many people saying it's impossible. :-)

Thanks. The EDID has the same info as the one I received from jizmodo. Which port of the Dell is the MacBook Air connected to? Can you get AGDiagnose from the other ports?

I read this document:

https://www.dell.com/support/article/ca/en/cadhs1/sln314416/dell-u4919dw-system-requirements-and-supported-configuration?lang=en

It mentions DisplayID version 1.3 supporting Tile Display but I don't see any Tile information yet. No MST info either.

GPU-Z doesn't show as much information for Intel graphics as it does for Nvidia or AMD graphics.

I see Dell Info shows only 3840x1080@60Hz in macOS but shows 5120x1440@60Hz in Windows. They both show USB-C DisplayPort 1.4 using HBR2 speed. What does the Color (Farbe) menu say?

In the Intel Graphics Control Panel, I see there are many refresh rate options for the 5120x1440@60Hz option. Did you try making a custom resolution yourself? Click "Custom Resolutions", then set Width to 5120, Height to 1440, Refresh Rate to 45, Timing Standard to CVT-RB, then click "Add". Click "Yes" to Continue. Does it work or give an error message?

The second AGDCDiagnose output is not significantly different from your first because you only changed the connection on the MacBook Air side. I was asking for information from the other ports of the display but maybe you don't have USB-C to DisplayPort or HDMI adapters? or an eGPU with DisplayPort or HDMI cables?

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.

My adapter is a thirdparty adapter. Not the original one.

There is a Displayport for this model but unfortunately I don't have such a cable from usb-c to displayport or an adapter.

I can try to boot Linux later today and give you feedback if it is working too.

Anyone out there happen to have access to the beta of 10.15.3? See any difference? If Apple created a workaround for the LD display in 10.15.2, I wonder if that means they are going to release additional workarounds for other ultrawide monitors in 10.15.3.

I am waiting for Type-C to Disport port cable arrive.

I dont think splitting it solve the problem.

I dont want to be solved.

I ONLY need Apple to solve the problem because it is their mistake, their false advisement.

After someday they may add the description of the mac as below:

Up to two displays:

One display with 5120-by-2880 resolution at 60Hz connected via Thunderbolt 3 plus one display with 4096-by-2160 resolution at 60Hz connected via HDMI 2.0

*Only apply to ratio at 16:9*

Note for Mac users:

https://www.dell.com/support/article/zh-hk/sln314416/dell-u4919dw-system-requirements-and-supported-configuration?lang=en&ref=topsolutions

If you are using an Intel Graphics card on your Mac, you will be able to display upto 3840 x 1080 resolution with the USB-C connection to the Dell U4919DW monitor.

For a higher resolution of 5120 x 1440 with the USB-C connection, use a Mac with a non-Intel discrete graphics card (NVIDIA or AMD).

PersistentOptimist wrote:

Note for Mac users:

https://www.dell.com/support/article/zh-hk/sln314416/dell-u4919dw-system-requirements-and-supported-configuration?lang=en&ref=topsolutions

If you are using an Intel Graphics card on your Mac, you will be able to display upto 3840 x 1080 resolution with the USB-C connection to the Dell U4919DW monitor.

For a higher resolution of 5120 x 1440 with the USB-C connection, use a Mac with a non-Intel discrete graphics card (NVIDIA or AMD).

I would be fine with answer that if it didn't work perfectly [5120 x 1440 resolution] on the exact same hardware (Mac Mini or MBP 13") running Windows 10. Try it. Boot Camp windows 10 on a Mac Mini or MBP 13" with the Intel graphics card and you will see that you can get 5120 x 1440 resolution no problem. The hardware is not the problem. It is capable of the desired resolution. Common sense would dictate that the issue is Mac OS. Unfortunately, Apple refuses to acknowledge / address / fix it.

"If you are using mac mini 2018 or older, Macbook air that without

external graphic card, you CANNOT use native 5120x1440 until you die

because the internal graphic card only support maximum up to 4096 x

2160. APPLE can never solve this."

We have already explained that this is nonsense. Apple itself advertises the Mini as compatible with 5k, which is 5120x2880. And again, technically display resolutions are a product from refresh rate x lines x pixels. In this way, even the cheap Intel graphics chips allow even unusual resolution ratios. (And they do using Windows 10 on a Mac with Intel Graphics - the 49" DELL works like a charme there)

Secondly, electronically there is no difference between a 4k and an 8k cable. it is just a question of shielding that allows higher data transfer rates.

The new 2020 MacBook Pro 13 inch has new 10th gen CPU with Gen11 graphics (don't get the MacBook Pro with the 8th gen CPU) which can support DisplayPort 1.4 and "Display Stream Compression" so it shouldn't have a problem with single link SST 6K (with DSC) or single link SST 5K displays.

MacBook has only USB-C. MacBook Air and MacBook Pro have Thunderbolt 3.

Thanks JeanLuc7. I realized after I made my original post I could test it out myself. As you posted that, I was testing PbP on a 27in LG display I already have. I currently have my 2019 13" MacBook Pro with Intel Graphics connected with 1 USB C cable and 1 Apple USB C > HDMI adapter + an Amazon HDMI cable.

1. I had a slight difference in color between the two monitors. (See in the video below) They both had the LG monitor's color profile. I didn't try to calibrate or fix.
2. When scrolling, I noticed some "tearing" where each page scrolled at a different speed. https://youtu.be/YNGpsfc83B4
3. As you mentioned there are two options: by default apps can only be on one screen, but going full screen only affects 1 app. If you disable "Displays have separate Spaces", apps can be on multiple screens, but going full screen "blacks out" the other screens. This is weird that you have to choose. On Windows, you have the best of both worlds without needing a setting. Apps can be between windows. Going full screen takes over only the monitor your app is mostly on. Back to Mac, I think maximizing instead of true full screen works for most apps. However it's annoying that Windows has best of both worlds, where as Mac forces you to choose. You also need to log out/in to change the setting.
4. I had a small bug where System Prefs would not let me drag the menu bar until I reverted to the original arrangement of the monitor. I was able to move the menu bar first THEN arrange the monitors.
5. The login screen is on one monitor. Again, minor quibble.
6. The default photo wallpaper makes the gap apparent - might want a flat color wallpaper.

I think I would keep the"Displays have separate Spaces" off and just maximize apps instead of proper full screen. Do you keep "Displays have separate Spaces" on or off?

Have you noticed the different colors and tearing when scrolling? That would probably be most annoying.

-Plaz