LG UltraFine 5K - Owners Thread

[eldho]

The box contents that the SSD came in lists it as "USB 3.2 Type-C to C cable" - please note the correction from what I put initially as 3.1, I also don't have any other connections at the back of the monitor. I have just looked up the internet to see that USB 3.2 runs effectively as a slower thunderbolt so I guess I got lucky with my trial.

 

[Ener Ji]

The box contents that the SSD came in lists it as "USB 3.2 Type-C to C cable" - please note the correction from what I put initially as 3.1, I also don't have any other connections at the back of the monitor. I have just looked up the internet to see that USB 3.2 runs effectively as a slower thunderbolt so I guess I got lucky with my trial.

That's interesting. Did the monitor itself work? At 5K resolution?

 

[eldho]

As far as I can tell, yes. The resolution shows as 2560 x 1440 and I think that is 2x. It is much clearer in fine detail than my previous 2011 iMac so believe it is working as expected. It is as clear as it was with the original cable that came with it but behaving better than it was. It would probably be fine with the cable it came with now given software updates but the shorter cable means less cable clutter on my desk.

 

[eldho]

Later on I remembered how to get the info from system settings and have cut and pasted the result below in confirmation of what I wrote before:

Displays:
LG UltraFine:
Resolution: 5120x2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60.00Hz

 

[etc]

Later on I remembered how to get the info from system settings and have cut and pasted the result below in confirmation of what I wrote before:

Displays:
LG UltraFine:
Resolution: 5120x2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60.00Hz

That's interesting. Did the monitor itself work? At 5K resolution?

No, through USB-C you won't get 5K. macOS tells you that's 5K, but in reality you see 5K downscaled to 4K, so the text has the same physical size, but a bit blurry - just because of 4K frame buffer.

 

[eldho]

It does seem a bit clearer with the original cable reinstalled. Thanks for that.

 

[joevt]

No, through USB-C you won't get 5K. macOS tells you that's 5K, but in reality you see 5K downscaled to 4K, so the text has the same physical size, but a bit blurry - just because of 4K frame buffer.

The frame buffer is 5K. The GPU scales it down to 4K. I don't know if there's a separate 4K framebuffer to hold the scaling result or if the GPU can just output the result without a second framebuffer.

The LG UltraFine 5K can do 5K over USB-C up to 39Hz. A Thunderbolt connection is required for 60Hz.

The Apple Studio Display can do 5K60 over USB-C using DSC.

 

[davideotape]

while this is a recent topic; I never got my issues fixed but I'm fine with Display buddy and just using this as a DDC. tried a few cables, maybe at some point I'll buy an official apple t4 cable but so far the $20 software is acceptable for me.

 

[Ener Ji]

So, a quick update:

I ended buying the hideously expensive TB4 cable from Apple (1m length), and the firmware update still doesn't work.

In better news, I've only tested a couple of times, but so far my monitor seems to be waking up much faster? That was the main reason I wanted to update the firmware anyway, so if the new cable continues to result in fast monitor wake-ups I'll be happy even if I can't update the firmware.

NB: I also updated to Sonoma 14.4.1 (from 14.3) so it's possible that's a factor in the faster wake-ups. At some point I'll try the original LG cable again to rule that out.

 

[hcm150056504]

Does anyone know that 27MD5KA supports automatic brightness adjustment under mac system? Does model A have an ambient light sensor? I bought a second-hand one but it cannot adjust the brightness automatically on Mac. Thanks

 

[hcm150056504]

Just got a used UltraFine 5k yesterday and the auto brightness has been driving me crazy.

It seems super sensitive, like just moving/turning my head a little bit causes the auto brightness to significantly increase/decrease the brightness.

I'm in a room that is pretty bright and gets a lot of sunlight but this is pretty annoying - my Mac screens dont fluctuate so much.

Anybody have similar experience or is something up with my monitor?

Does your auto-brightness work? Are you a 27MD5KA model or a 27MD5KL model? In the system settings - is there an automatic brightness adjustment switch in the monitor?

Regarding your overly sensitive problem, I think you can put a translucent tape on the light sensor, haha

 

[zevrix]

Does anyone know that 27MD5KA supports automatic brightness adjustment under mac system? Does model A have an ambient light sensor? I bought a second-hand one but it cannot adjust the brightness automatically on Mac. Thanks

I don't know if this is of any help, but 2 years ago I returned a new LG 27MD5KL-B due to a brightness issue: after my Mac Studio would wake up, the brightness was always at its highest value no matter how it was adjusted before the Mac went to sleep.

I spent several days trying to solve the issue with various adjustments and 3rd-party tools with no luck.

But by that time, however, I already learned (in part thanks to other MacRumors members) something I didn't know before I bought the monitor: that the difference between 4K and 5K is indistinguishable to the human eye under regular viewing conditions.

So I happily returned this monitor for a full refund and bought a 4K Dell monitor that was about 4 times cheaper. So in the end I'm so happy the UltraFine had this brightness problem - it saved me tons of money in the end.

 

[etc]

that the difference between 4K and 5K is indistinguishable to the human eye under regular viewing conditions.

The noticeable difference between 4k and 5k is in the usable area, and not in pixel density - although that too, and even if we compare monitors with the same diagonal.

4k is just an analogue of FullHD with double pixel density. 5k is an analogue of 2560x1440 pixels of usable area - a third more than 4k. This is why people pay extra for 5k.

 

[joevt]

The noticeable difference between 4k and 5k is in the usable area, and not in pixel density - although that too, and even if we compare monitors with the same diagonal.

4k is just an analogue of FullHD with double pixel density. 5k is an analogue of 2560x1440 pixels of usable area - a third more than 4k. This is why people pay extra for 5k.

If someone has a 4K 27 inch display, then they are probably using it with a 5120x2880 looks like 2560x1440 image. In that case, people pay for 5K to get a slightly better image than 4K rather than more usable area.

 

[etc]

If someone has a 4K 27 inch display, then they are probably using it with a 5120x2880 looks like 2560x1440 image. In that case, people pay for 5K to get a slightly better image than 4K rather than more usable area.

Yes, but it'll be blurry anyway and just ugly.

 

[eldho]

I don't know if this is of any help, but 2 years ago I returned a new LG 27MD5KL-B due to a brightness issue: after my Mac Studio would wake up, the brightness was always at its highest value no matter how it was adjusted before the Mac went to sleep.

Mine used to do this too but a software update solved this problem so that it now always wakes up to exactly the setting that it was when it went to sleep. It was quite a relief for me when that irritation finally ended.

 

[zevrix]

zevrix said:
that the difference between 4K and 5K is indistinguishable to the human eye under regular viewing conditions.

The noticeable difference between 4k and 5k is in the usable area, and not in pixel density - although that too, and even if we compare monitors with the same diagonal.

4k is just an analogue of FullHD with double pixel density. 5k is an analogue of 2560x1440 pixels of usable area - a third more than 4k. This is why people pay extra for 5k.

Ok I see yeah I'm sure that users who have some more advanced requirements for their monitors have special reasons to use 5K over 4K. All kind of advanced discussions of monitor pixel density are way over my head (for example, I have no idea what "4k is just an analogue of FullHD with double pixel density" means.)

All I know is that I'm using 27" 4K Dell monitor at 2560x1440. I ran tests comparing it to 5K LG UltraFine at the same screen area — and my eye couldn't detect any difference in image quality under normal viewing conditions. If I nearly press my eye to the monitor then yes I could see that 4K is kinda more pixelated. Once again, this difference disappears to me under a standard viewing distance.

 

[oKUtItyp]

New owner here.

Where I can find firmware changelog? the one inform me to upgrade is (3.04,2.23,5250,4.13,0.3,43,6.59)

 

[eldho]

New owner here.

Where I can find firmware changelog? the one inform me to upgrade is (3.04,2.23,5250,4.13,0.3,43,6.59)

To upgrade the only way I know is to download LG Screen Manager from the app store and run that app. It takes a while - half a minute or so - to tell you what you are on and to give you update options. My up to date version is (3.14,2.23 etc)

 

[Quotenfrau]

I have a very complicated request: I want to connect two devices in parallel to UltraFine 5k. I would then like to be able to switch between the two devices, how can I do this? One device is MacBook Air and the second is Linux

 

[Ener Ji]

So, a quick update:

I ended buying the hideously expensive TB4 cable from Apple (1m length), and the firmware update still doesn't work.

In better news, I've only tested a couple of times, but so far my monitor seems to be waking up much faster? That was the main reason I wanted to update the firmware anyway, so if the new cable continues to result in fast monitor wake-ups I'll be happy even if I can't update the firmware.

NB: I also updated to Sonoma 14.4.1 (from 14.3) so it's possible that's a factor in the faster wake-ups. At some point I'll try the original LG cable again to rule that out.

So just a quick update - I was able to update my firmware today! I'm not exactly sure what changed to allow it to happen as it's failed repeatedly for me, even after I purchased a brand new Apple TB4 cable.

I shut down my computer last night (rare for me, usually it's in standby mode with the occasional reboot). Today when I started it up, the LG Screen Manager loaded (it starts at login) and prompted me to update the firmware. It's failed many, many times before but I decided what the heck, let me try one more time, and for some reason this time it worked. 🤷‍♂️
Screenshots of my firmware before and after are below:

After​

Before​

 

[jterp7]

yeah mine failed just once but i was worried reading yours. I did leave my macbook air closed contrary to the instructions.