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

[oddbjornk]

After reading your reply, I checked the bios and realized that Thunderbolt Boot support: Enabled was not turned on, and when it was turned on, my microphone, etc. worked fine too~

@aha081: Nice! Does your system suffer from the same problems I’ve been seeing; all good on cold boot, but only 50% success rate on reboots or sleep/wake?

 

[Eric_WVGG]

Hi! I just thought I'd report that I am using the LG Ultrafine 5k (27MD5KL-B) with Windows 11 in its full 5120x2880 glory with webcam, speakers and USB-hub all ok.

My hardware:
Motherboard: ASUS ROG STRIX Z490-A GAMING
GPU: ASUS ROG Strix GeForce RTX 2060 OC
Thunderbolt expansion card: ASUS ThunderboltEX 3-TR
Display: LG 5K Ultrafine 27MD5KL-B

… gawd, that sounds like exactly what I need… except I have a Mini ITX build with only one PCI-Express slot 🤪

 

[aha081]

@aha081: Nice! Does your system suffer from the same problems I’ve been seeing; all good on cold boot, but only 50% success rate on reboots or sleep/wake?

I've had it where the computer runs normally after sleep mode startup but the screen is unresponsive, I looked into it and found out it was a windows wakeup issue, turned off the network card (and possibly other devices) in the settings to allow the computer to turn off this device to conserve power and it hasn't come up since.

 

[oddbjornk]

BUT: today I discovered that if I have another monitor connected to the HDMI output of the Nvidia card everything works perfectly even after reboots!

Replying to my own post, I can add that I today have verified that using a HDMI dummy/emulator plugged directly in the graphics card works just as well as the Dell monitor I used earlier. The Thunderbolt connected display works consistently well on cold boots, reboots and wake from sleep.

 

[lilliputian]

I'd rather try a straight HDMI 2.0 to USB-C adapter like this one. The fewer adapters/converters, the better. Do you have a HDMI monitor to test if the laptop is providing video output via HDMI?

Going back to the straight USB-C connection for now:

1. Are you using the same USB-C cable that works in conjunction with your MacBook Pro?

2. Is the monitor being detected in Windows' display properties at all? If so, is Windows set to expand the desktop to the monitor?

3. Have you tried playing with the Intel graphics driver's settings panel to see if the monitor needs to be enabled manually (shouldn't be necessary but you never know...)?

4. Do you have another DisplayPort or USB-C monitor to test if the laptop is providing video output via USB-C in the first place? It is not impossible that this has been disabled, either through an UEFI firmware setting or other setting, by your employer.

Does the CAC-1333 seem to be functionally equivalent to the CAC-1332 in your estimate? The 1332 doesn't seem to be available anywhere obvious (Amazon/Ebay/Newegg).

 

[joevt]

Does the CAC-1333 seem to be functionally equivalent to the CAC-1332 in your estimate? The 1332 doesn't seem to be available anywhere obvious (Amazon/Ebay/Newegg).

CAC-1333 is missing USB 2.0 input so you won't get USB features from a connected USB-C display (audio, camera, USB ports, etc.)
I think both of those are limited to 4K width.

Maybe try CAC-1336.
https://insights.club-3d.com/thread/cac-1336-operation/

 

[lilliputian]

After testing the Club3D CAC-1336 with a 20Gbps USB-C cable from Cable Matters, we got mixed results using 2015 MBPs with built-in HDMI (limited or no display options, or the monitor doesn't turn on but shows up in the Display control panel), but unfortunately nothing is output from a MacPro 5,1 equipped with an Nvidia GeForce GTX 780 graphics card (the MacPro 5,1 is running Monterey via OCLP).

It was mentioned previously that a bi-directional DisplayPort-to-USB-C cable should also work, though the GTX 780 is limited to DisplayPort 1.2 it would seem. Elsewhere in the thread it has been mentioned that it should be possible to get full 5k support if one uses two DisplayPort 1.2 ports at once, although the GTX 780 only has the one.

Will the LG UltraFine work at all with just a single DP 1.2 port? We're not particularly concerned about getting the full 5k that the monitor was designed for as it was a freeby; any output will be an upgrade from the current display setup on the MacPro (a cheap 1080p Vizio TV!).

 

[etc]

After testing the Club3D CAC-1336 with a 20Gbps USB-C cable from Cable Matters, we got mixed results using 2015 MBPs with built-in HDMI (limited or no display options, or the monitor doesn't turn on but shows up in the Display control panel), but unfortunately nothing is output from a MacPro 5,1 equipped with an Nvidia GeForce GTX 780 graphics card (the MacPro 5,1 is running Monterey via OCLP).

It was mentioned previously that a bi-directional DisplayPort-to-USB-C cable should also work, though the GTX 780 is limited to DisplayPort 1.2 it would seem. Elsewhere in the thread it has been mentioned that it should be possible to get full 5k support if one uses two DisplayPort 1.2 ports at once, although the GTX 780 only has the one.

Will the LG UltraFine work at all with just a single DP 1.2 port? We're not particularly concerned about getting the full 5k that the monitor was designed for as it was a freeby; any output will be an upgrade from the current display setup on the MacPro (a cheap 1080p Vizio TV!).

It should work with belkin vr cable or wacom link plus as usb-c with displayport alt mode at 4k (dp 1.2 can handle it)

 

[lilliputian]

So something like this would not work with the LG UltraFine over just DP 1.2?

 

[etc]

So something like this would not work with the LG UltraFine over just DP 1.2?

Well, it should. I have moshi usb-c dp cable and it worked. But you won't be able to control brightness or use camera

 

[lilliputian]

So it seems the problems with this monitor never cease.

I ended up following instructions from NorthridgeFix on Youtube for reflowing the Thunderbolt connector (as apparently pins separating is a common problem). Lo and behold, after I got everything back together again last night, I had restored picture to the monitor (using the Club3D/USB-C combo with my 2015 MBP).

Fast forward to this morning, I think to myself: "That's right, there's a specific application for managing the monitor, let's open that up", to which I was presented with a prompt to update the firmware for the monitor. Naively, I said yes, only for it to get "interrupted" partway through (another common problem, I would learn), leaving the monitor in a weird state (as is often the case with botched firmware updates).

It is sometimes detected by the host system, sometimes not. When it is, I get no picture, though my list of resolutions has expanded from exactly one (1), to a huge range of resolutions, some of which seem to be bigger than the monitor should actually be able to support (including 8k?).

Long story short: the LG software supports applying a file as an update manually, but these files seem to be impossible to find. Would anyone be able to point me to the latest firmware update for the UltraFine "27MD5KLB"?

EDIT: Re-plugged it once again. Still no picture, but the detected available resolutions now back to one (1280x720??).

EDIT2: Restarting while the monitor is detected restores the full list of resolutions, but still no picture...

 

[etc]

So it seems the problems with this monitor never cease.

I ended up following instructions from NorthridgeFix on Youtube for reflowing the Thunderbolt connector (as apparently pins separating is a common problem). Lo and behold, after I got everything back together again last night, I had restored picture to the monitor (using the Club3D/USB-C combo with my 2015 MBP).

Fast forward to this morning, I think to myself: "That's right, there's a specific application for managing the monitor, let's open that up", to which I was presented with a prompt to update the firmware for the monitor. Naively, I said yes, only for it to get "interrupted" partway through (another common problem, I would learn), leaving the monitor in a weird state (as is often the case with botched firmware updates).

It is sometimes detected by the host system, sometimes not. When it is, I get no picture, though my list of resolutions has expanded from exactly one (1), to a huge range of resolutions, some of which seem to be bigger than the monitor should actually be able to support (including 8k?).

Long story short: the LG software supports applying a file as an update manually, but these files seem to be impossible to find. Would anyone be able to point me to the latest firmware update for the UltraFine "27MD5KLB"?

EDIT: Re-plugged it once again. Still no picture, but the detected available resolutions now back to one (1280x720??).

EDIT2: Restarting while the monitor is detected restores the full list of resolutions, but still no picture...

Sounds like the tb connector is still damaged

 

[lilliputian]

For what it's worth, it stopped showing picture prior to unplugging from the display itself...

 

[omniatlas]

I switched from the Wacom Link Plus to the "WJESOG DisplayPort to USB C Cable 6.6ft 4K@60Hz with USB Cable Adapter,DP Male to Type-C"; using it to connect my LG 4K monitor to a Windows PC.

With the Wacom the dongle wasn't reliable and I would get blank screens or BIOS wouldn't show at times. The dongle wire mess was also anonying.

The WJESOG eliminates all of these problems; no issues so far!