LG UltraFine 4K and 5K: Yes you can connect it to Windows computers via DP!!!

[joevt]

I tried the 5k39 option (it showed up on the monitor connected with USB-C not the TB3 connected monitor). But it didn't work.

Ok, next step would be to use SwitchResX on macOS or CRU in Windows to create 5120x2880 timings between 30Hz and 38Hz using CVT-RB timing. And test each one. Maybe CVT-RB v2 might give an extra frame per second.

OK I i got them working again while maintaining the EDID file in effect after restarts etc. But now the audio doesn't work as well (it still loads but buffers intermittently like broken speakers). It was fine all along until all the maneuvers/changes I did. It's happening on both monitors. any ides?

I don't see any reason for audio to be affected. It's a USB device. Probably USB 2.0 so it doesn't require much bandwidth (check macOS System Information.app's USB tab).
4K60 10bpc = 16 Gbps
5K39 8bpc = 14.5 Gbps
Those leave enough bandwidth for a 20 Gbps connection to do audio.

 

[cdf]

I'm trying to use an LG UltraFine 4K (24MD4KL) with a MacPro5,1 in macOS. This is what I'm trying to achieve:

• DP+USB 3.x to display
• pre-boot environment displayed during both cold and warm boots
• perfectly working brightness and audio controls

I've tested three solutions, all of which fall short of satisfying my criteria:

1. Wacom Link Plus: This solution is limited to USB 2.0 and causes crackling audio.
2. GC-TITAN RIDGE with a USB-C 3.1 cable: This solution fails to display the pre-boot environment during cold boots, though once the OS is booted, the DP conversion starts working, and keeps working through warm boots. Also, the brightness and audio controls require a reboot before they start working.
3. GC-TITAN RIDGE (Mac firmware) with a Thunderbolt 3 cable: This solution requires unplugging and replugging the cable on a cold boot. Also, the brightness and audio controls require a reboot before they start working.

Now I'm looking at the Sunix UPD2018. @joevt with all your knowledge in this area, would you happen to know if this device would satisfy my criteria? Since this device can do DP conversion even without a PCIe connection, I'm hoping that it will work like solution 2, but without the shortcomings.

 

[Amethyst1]

Now I'm looking at the Sunix UPD2018.

Connecting the 24MD4KL via USB-C (doesn't matter what you connect it to) limits its downstream USB ports to USB 2.0:

The LG UltraFine 4K is like a Thunderbolt dock that is compatible with USB-C. As a USB-C device (not Thunderbolt) the LG UltraFine 4K expects 4 lanes of DisplayPort 1.2 with USB 2.0

 

[joevt]

I'm trying to use an LG UltraFine 4K (24MD4KL) with a MacPro5,1 in macOS. This is what I'm trying to achieve:

• DP+USB 3.x to display
• pre-boot environment displayed during both cold and warm boots
• perfectly working brightness and audio controls

I've tested three solutions, all of which fall short of satisfying my criteria:

1. Wacom Link Plus: This solution is limited to USB 2.0 and causes crackling audio.
2. GC-TITAN RIDGE with a USB-C 3.1 cable: This solution fails to display the pre-boot environment during cold boots, though once the OS is booted, the DP conversion starts working, and keeps working through warm boots. Also, the brightness and audio controls require a reboot before they start working.
3. GC-TITAN RIDGE (Mac firmware) with a Thunderbolt 3 cable: This solution requires unplugging and replugging the cable on a cold boot. Also, the brightness and audio controls require a reboot before they start working.

Now I'm looking at the Sunix UPD2018. @joevt with all your knowledge in this area, would you happen to know if this device would satisfy my criteria? Since this device can do DP conversion even without a PCIe connection, I'm hoping that it will work like solution 2, but without the shortcomings.

4K60 + USB 3.0 requires Thunderbolt connection which Sunix cannot do.

GC-TITAN RIDGE probably requires some UEFI code to enable it at startup. It should be simple to start it up for pre-boot screen (I'm not sure why it wouldn't work already). Getting it's USB ports to work at pre-boot will be more difficult (maybe pre-boot screen doesn't work because USB isn't working).

 

[cdf]

Thanks for the responses! Things are making much more sense now.

Connecting the 24MD4KL via USB-C (doesn't matter what you connect it to) limits its downstream USB ports to USB 2.0:

That explains why the connection appears through a USB 2.1 hub when connected via USB-C. So that's another shortcoming of solution 2. If Thunderbolt is the only option here, then perhaps I should remove the requirement for USB 3.x. In that case, the Wacom Link Plus might actually be the best solution, if the crackling audio can be fixed.

4K60 + USB 3.0 requires Thunderbolt connection which Sunix cannot do.

Right. So other than possibly fixing the crackling audio, there would be no advantage over the Wacom Link Plus.

Regarding the crackling audio, it seems that the shorter the cable (USB-A to micro USB) the less the crackling, but short unshielded cables are still problematic. Could this be an electromagnetic compatibility issue? The cable that comes with the Wacom Link Plus has a ferrite choke on it, but for some reason, that cable causes an issue on the USB bus to which it's connected: all the other ports on that bus stop working properly. I wonder if this would help:

Filter Stick USB 2.0 Type A EMC | Passive Components | Würth Elektronik Product Catalog

Filter Stick USB 2.0 Type A EMC. All the details on our product families in the Würth Elektronik catalog.

www.we-online.com

GC-TITAN RIDGE probably requires some UEFI code to enable it at startup. It should be simple to start it up for pre-boot screen (I'm not sure why it wouldn't work already).

I wonder if drivers from Mac firmware could be used. There has been some success in this direction:

[SUCCESS] Gigabyte Designare Z390 (Thunderbolt 3) + i7-9700K + AMD RX 580

192khz holy wow. Any idea how we can check the sample rate of a .movpkg "file" ? (of course I checked every file from the screenshot)

www.tonymacx86.com

Getting it's USB ports to work at pre-boot will be more difficult (maybe pre-boot screen doesn't work because USB isn't working).

As far as I known, there are no USB 3.x EFI drivers compatible with the Mac Pro 5,1. I'm fine with not having USB at preboot. It's just unfortunate that a reboot is required to get brightness and audio controls.

 

[royas]

Hello,

I have a DELL Latitude 5420. It has two 2 Thunderbolt 4 ports with DisplayPort Alt Mode/USB4/Power Delivery.

Would I be able to connect the following Ultrafine models: 27MD5KA (5k old model) and 22MD4KA (4k) at the same time?

Thunderbolt 4 should be backwards compatible with Thunderbolt 3, or am I wrong?

​

I would appreciate any help !

 

[Amethyst1]

Would I be able to connect the following Ultrafine models: 27MD5KA (5k old model) and 22MD4KA (4k) at the same time?

If you have a 10th-gen CPU, you can hook up two external displays (three if the laptop display is off). The UltraFine 5K already counts as two 2560×2880 displays, so you won't be able to also hook up the UltraFine 4K unless you disable the laptop display.
If you have an 11th-gen CPU, you can hook up three external displays (four if the laptop display is off). The UltraFine 5K already counts as two 2560×2880 displays, so you should be able to also hook up the UltraFine 4K.

Source: https://dl.dell.com/topicspdf/latitude-5420-laptop_owners-manual_en-us.pdf (page 22)

The UltraFine 5K requires two DisplayPort connections to be routed to a single Thunderbolt 3/4 port - if this is not the case, it will only run at "4K" resolution.

 

[royas]

If you have a 10th-gen CPU, you can hook up two external displays (three if the laptop display is off). The UltraFine 5K already counts as two 2560×2880 displays, so you won't be able to also hook up the UltraFine 4K unless you disable the laptop display.
If you have an 11th-gen CPU, you can hook up three external displays (four if the laptop display is off). The UltraFine 5K already counts as two 2560×2880 displays, so you should be able to also hook up the UltraFine 4K.

Source: https://dl.dell.com/topicspdf/latitude-5420-laptop_owners-manual_en-us.pdf (page 22)

The UltraFine 5K requires two DisplayPort connections to be routed to a single Thunderbolt 4 port - if this is not the case, it will only run at "4K" resolution.

Cool thank you very much for your help! Would've been difficult for me to find this out by myself.

I am lucky as my Dell Latitude 5420 has an 11th gen CPU, so I should be fine.

Would the Webcam also work when I connect my Dell? Or is that only possible with Macs?

Other than that, it is interesting that you mentioned the Ultrafine 5K counts as two displays. I've heard that it is not possible, for example, to connect an M1 Air to two monitors. But somehow I suppose it works?

 

[joevt]

As far as I known, there are no USB 3.x EFI drivers compatible with the Mac Pro 5,1. I'm fine with not having USB at preboot. It's just unfortunate that a reboot is required to get brightness and audio controls.

True. Code exists for UEFI USB 3.x drivers but it needs modification to work with EFI 1.x and even then there are some issues. It's a work in progress.

During first boot, the Thunderbolt chain is not setup until the OS starts. The OS sets up the Thunderbolt chain. All the PCIe devices are probably accessible at this time but macOS doesn't enumerate them. I suppose some kext could be made to do that. The second boot has the Thunderbolt chain already setup so UEFI can enumerate the PCIe devices in the Thunderbolt chain including the USB controller in the display which has a Usb hub connected to it and the USB devices for brightness control, audio, and camera connected to that hub.

I have a DELL Latitude 5420. It has two 2 Thunderbolt 4 ports with DisplayPort Alt Mode/USB4/Power Delivery.

Would I be able to connect the following Ultrafine models: 27MD5KA (5k old model) and 22MD4KA (4k) at the same time?

Thunderbolt 4 should be backwards compatible with Thunderbolt 3, or am I wrong?

​

I would appreciate any help !

Each Thunderbolt 4 port of the Dell can have 2 displays connected to it. But what is the total number of displays that can be connected? I think Intel graphics is limited to 3 displays?

The 5K counts as 2 displays. The internal display counts as one. Maybe if you close the laptop lid, it will disable the internal display so then you can connect the 5K and 4K.

You can try connecting the 5K with a USB-C cable (non-thunderbolt) cable. It will limit the Thunderbolt connection to 20 Gbps so that the display can only use up one DisplayPort HBR2 connection. It will be limited to 4K60 though, unless you can get a lower 5K refresh rate to work such as 5K39. One person got 5K39 working with a new 5K model 27MD5KL. I don't think anyone has tried getting 5K30-5K39 working on the old 5K model. Use CRU to create the 5K timings between 30 and 40Hz and see if any of them work while connected at 20 Gbps.

Would the Webcam also work when I connect my Dell? Or is that only possible with Macs?

I think the camera is a normal USB camera so you don't need extra drivers for that (just like audio is a normal USB audio device). If it's not then you would need to install the Boot Camp drivers. You should probably do that anyway for brightness control.
https://github.com/timsutton/brigadier

Other than that, it is interesting that you mentioned the Ultrafine 5K counts as two displays. I've heard that it is not possible, for example, to connect an M1 Air to two monitors. But somehow I suppose it works?

The first M1 Macs had two DisplayPort connections to the Thunderbolt controller but the second connection can only be used by a dual link SST display such as the LG UltraFine 5K or Dell UP2715K.

The M1 Pro and M1 Max may be similar. It appears that there are extra DisplayPort connections so a display like LG UltraFine 5K can be connected without reducing the number of displays that can be connected by more than 1. If you can connect three LG UltraFine 5K to the M1 Max at full 5K60, then it would mean that it has 6 or 7 DisplayPort connections. No one has posted sufficient evidence yet (such as an ioreg dump or a save from IORegistryExplorer.app or screenshots of timing info in SwitchResX for each LG UltraFine 5K display). I could use the ioreg dump to update my script at https://gist.github.com/joevt/e862b0088ef58b9144877d01401bcee8

 

[joevt]

Updated my last post to say three LG UltraFine 5K displays (since M1 Max only has 3 TB4 ports). The question is how many DisplayPort connections does the M1 Max have when considering dual link SST displays like the LG UltraFine 5K or Dell UP2715K? We know the number is at least 4 to allow connecting four single link SST displays. But if you can connect 3 dual link SST displays (one to each TB4 port) and get full 5K60 10bpc RGB from all of them then the number would be 6 (or 7 if the HDMI port still allows a connection).

 

[Amethyst1]

I think Intel graphics is limited to 3 displays?

The Iris Xe GPU raises that to 4 [Source (page 3)].

 

[camhabib]

Hoping someone who has been keeping up with this thread can help me out. I have an older non-Mac laptop with only an HDMI out that I'm trying to hook up to my Ultrasharp 5k. Is there any easy way, or even any way at all, to do this?

 

[Amethyst1]

I have an older non-Mac laptop with only an HDMI out that I'm trying to hook up to my Ultrasharp 5k. Is there any easy way, or even any way at all, to do this?

If you have the older UltraFine 5K (27MD5KA) that requires Thunderbolt 3 input: You need an HDMI to DisplayPort converter (like this one) and a Thunderbolt 3 add-in card (like the Gigabyte GC-TITAN RIDGE), installed in e.g. a powered riser. You'll be limited to "4K" resolution, if it works in the first place.

If you have the newer UltraFine 5K (27MD5KL) that can also take USB-C input: You just need an HDMI to USB-C converter like this one. You'll be limited to 4K resolution.

Does your laptop have HDMI 2.0 so you can get "4K" at 60 Hz? If it doesn't, you'll be stuck with 2560×1440 at 60 Hz or "4K" at 30 Hz...

 

[royas]

[...]

You can try connecting the 5K with a USB-C cable (non-thunderbolt) cable. It will limit the Thunderbolt connection to 20 Gbps so that the display can only use up one DisplayPort HBR2 connection. It will be limited to 4K60 though, unless you can get a lower 5K refresh rate to work such as 5K39. One person got 5K39 working with a new 5K model 27MD5KL. I don't think anyone has tried getting 5K30-5K39 working on the old 5K model. Use CRU to create the 5K timings between 30 and 40Hz and see if any of them work while connected at 20 Gbps.


[...]

Thank you very much for your detailed response. I am really impressed with your knowledge about monitors.

One more question, if you don't mind, do I understand correctly that I won't be able to do 5K60HZ with Windows/Thunderbolt 4? Or is this 5K39 limitation only in case using a USB C cable?

 

[joevt]

One more question, if you don't mind, do I understand correctly that I won't be able to do 5K60HZ with Windows/Thunderbolt 4? Or is this 5K39 limitation only in case using a USB C cable?

Windows can do 5K60 on the LG UltraFine 5K with a 40 Gbps Thunderbolt 3/4 cable if it's connected to a Thunderbolt 4 port or a Thunderbolt 3 port that supports two displays.

The 5K39 limit is for Thunderbolt 3 or Thunderbolt 2 ports that only support one DisplayPort 1.2 connection or if you force a 20 Gbps connection by using a USB-C (non-Thunderbolt cable) or by using a Thunderbolt cable that's rated for only 20 Gbps.

 

[Robertttttt]

I have tested Sonix UPD2018 is worked on the 23.7-inch model. Smooth brightness and sound control on macOS, although I have a pair of additional speakers. Windows do not support USB function.

 

[joevt]

Windows do not support USB function.

Which USB function? Did you test any other USB devices with the Sunix UPD2018?

 

[Artem1989]

Tell me what program you need to install to adjust the brightness in windows? And where to download it? I did not find it on the lg official website.

 

[joevt]

Tell me what program you need to install to adjust the brightness in windows? And where to download it? I did not find it on the lg official website.

I think you need the boot camp driver. Search for other posts where people have tried it.
https://github.com/timsutton/brigadier

 

[captainb8]

Tell me what program you need to install to adjust the brightness in windows? And where to download it? I did not find it on the lg official website.

I downloaded the LG OnScreen Control utility from here: https://www.lg.com/us/support/product/lg-27MD5KA-B.AUS and it works perfectly to adjust the brightness on my Ultrafine 5K (27MD5KL-B) connected to my work-provided Windows 10 HP ZBook 15u G6, connected via the USB-C cable provided with the monitor.

 

[joevt]

I downloaded the LG OnScreen Control utility from here: https://www.lg.com/us/support/product/lg-27MD5KA-B.AUS and it works perfectly to adjust the brightness on my Ultrafine 5K (27MD5KL-B) connected to my work-provided Windows 10 HP ZBook 15u G6, connected via the USB-C cable provided with the monitor.

Right. The Boot Camp drivers I mentioned would more useful for Apple's displays.

 

[TYoung96]

Wow this thread is great!
I have an ASRock X570 itx/tb3 mobo, the tb3 port will run one of my LG 24MD4KL-B monitors, but not both if they're daisy chained, (My Macbook does this fine). As fair as I can tell I can just use and ALOGIC usb-c to DP cable directly from my GPU?

Otherwise I need the Wacom Link Plus? Not fussed about loosing the usb hub from the monitor

 

[OoklaTheMok]

Having read a lot of the posts, I’m planning to get the LG 21.5 4K monitor to use VESA-mounted in portrait mode with my 1st-gen 2014 iMac 5K, which only has Thunderbolt 2/MiniDP. I’ll replace the iMac when the Apple Silicon 27”+ version comes out, and I presume the USB-C cable will work then. But until then I will use adapters.

The only cables that have been listed as working are the ALOGIC and AmazonBasics USB-C to DisplayPort. Is there a recommended Thunderbolt 2/MiniDP male to DisplayPort female adapter people have used successfully? The ones I check on Amazon, the 1-star reviews scare me, haha. Or, are there any bidirectional MiniDP-USB-C cables that have been found to work?

 

[joevt]

For best results, I would connect a USB-C display to a Thunderbolt 3 dock or device that has a 2nd Thunderbolt port (connect the Thunderbolt 3 device to the Thunderbolt 2 Mac using an Apple Thunderbolt 3 to Thunderbolt 2 Adapter). This will allow all the USB functions of the display to work (audio, camera, USB ports, brightness control). A Thunderbolt 4 dock might also work (if you're running Big Sur or later) but I don't have a Thunderbolt 2 Mac to test it with - it does not work with a Thunderbolt 1 Mac.

There are some other ideas at https://egpu.io/forums/gpu-monitor-...sb-c-to-displayport-cable/paged/4/#post-79127

 

[OoklaTheMok]

For best results, I would connect a USB-C display to a Thunderbolt 3 dock or device that has a 2nd Thunderbolt port (connect the Thunderbolt 3 device to the Thunderbolt 2 Mac using an Apple Thunderbolt 3 to Thunderbolt 2 Adapter). This will allow all the USB functions of the display to work (audio, camera, USB ports, brightness control). A Thunderbolt 4 dock might also work (if you're running Big Sur or later) but I don't have a Thunderbolt 2 Mac to test it with - it does not work with a Thunderbolt 1 Mac.

There are some other ideas at https://egpu.io/forums/gpu-monitor-...sb-c-to-displayport-cable/paged/4/#post-79127

Thanks. I’ll look into those options. (I did read that egpu thread before.) Though, I use the MacOS app Lunar to control an external monitor’s brightness level through DCC, like the Windows app mentioned in the first post in this thread. It works really great for my existing external monitor.

And, the iMac 5K already has great speakers, and since I’ll be suing the LG in portrait node, terror audio would be messed up. Same with the camera—the iMac has a great one. So the only advantage would be the USB ports, and there’s nothing I want to plug in.

So, it seems like if there’s just a one-cable solution it will be cheaper than a Thunderbolt dock. And if there’s not a one-cable solution, then knowing whether there is a recommended MiniDP to DisplayPort adapter would be helpful.