LG's New UltraFine 5K Display Limited to 4K Resolution When Used With 2018 iPad Pro

[barefeats]

Testing one. Only a portion of the LG screen is used when just mirroring the "home" screen of the latest 12.9-inch iPad Pro running iOS 13.0 beta. However, when I run Real Racing 3, the LG's screen fills up with the racing animation while the iPad Pro is relegated to selecting the car and racing venue. The LG also charges the iPad Pro.

The 5K Dell UP2715K display does the same thing when its mini DisplayPort cable is used with a mDP-to-USB-C adapter. However, it does not charge the iPad Pro.
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[doublepost=1564584581][/doublepost]Humm...wonder if it works with the Mac Pro 2013? The previous one did...

Yes, it works. In fact, I'm using two LG 5K UltraFine displays with the 2013 Mac Pro. One is newest model and one is the previous model.

 

[barefeats]

I’m using the dell up2715k which was sadly discontinued.. but I’m glad about it because it does look nicer in my opinion. Still no match to the thunderbolt displays I had before though of course...

I'm also using a Dell UP2715K as well as the old and new LG UltraFine 5K. The Dell supports the iPad Pro using the mini DisplayPort cable with mDP-to-USB-C adapter.

 

[joevt]

The 5K Dell UP2715K display does the same thing when its mini DisplayPort cable is used with a mDP-to-USB-C adapter. However, it does not charge the iPad Pro.

I'm also using a Dell UP2715K as well as the old and new LG UltraFine 5K. The Dell supports the iPad Pro using the mini DisplayPort cable with mDP-to-USB-C adapter.

The Dell should tell you what resolution its using when you display the on screen menu. It might not show the timing (refresh rate) if it's an HD resolution it won't say if you're using 4K 30 Hz or 4K 60 Hz. Does the new LG have an onscreen menu?

 

[barefeats]

Keynote and iMovie on the iPad Pro are able to use the latest LG UltraFine 5K to play or preview a project using the full screen. And the iPad Pro becomes the control pad to advance slides in Keynote or play/pause/rewind the movie in iMovie.
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The Dell should tell you what resolution its using when you display the on screen menu. It might not show the timing (refresh rate) if it's an HD resolution it won't say if you're using 4K 30 Hz or 4K 60 Hz. Does the new LG have an onscreen menu?

The Dell UP2715K 27-inch indicates in the Menu > Input Source that the mDP supports 4K and 2K but does not indicate which resolution is in use. However, when I use it to run Keynote slides or Real Racing 3, it clearly appears to be running at 4K.

 

[joevt]

The Dell UP2715K 27-inch indicates in the Menu > Input Source that the mDP supports 4K and 2K but does not indicate which resolution is in use.

Look at the bottom left corner of the main menu, not the Input Source menu. If it's running at 4K then it should say 2160p.

The Input Source menu just indicates that dual DisplayPort is required for 5K3K and mini DisplayPort is limited to 4K2K.

 

[barefeats]

Look at the bottom left corner of the main menu, not the Input Source menu. If it's running at 4K then it should say 2160p.

The Input Source menu just indicates that dual DisplayPort is required for 5K3K and mini DisplayPort is limited to 4K2K.

Dell UP2715K Main Menu indicates Resolution: 3840x2160, 60Hz when mDP cable connected to the 2018 iPad Pro 12.9-inch

 

[joevt]

Dell UP2715K Main Menu indicates Resolution: 3840x2160, 60Hz when mDP cable connected to the 2018 iPad Pro 12.9-inch

Since it tells you the resolution and refresh rate instead of just "2160p", I think that means it's using the DisplayPort 4K timing (533 MHz pixel clock - same as CVT-RB timing) instead of HDMI 4K timing (594 MHz). Or I could be wrong - I can see "2160p" only on my Dell P2415Q when using the HDMI input, regardless of the timing or refresh rate. I can't get "2160p" to appear on the DisplayPort inputs of the P2415Q or UP2715K even after adding HDMI timings copied from the P2415Q. Oh, wait, now I can get "2160p" to appear in the menu when using the DisplayPort input of the P2415Q but now I can't get the menu to show "3840x2160, 60Hz". I don't know what's going on... Ok, using "Restore Factory Settings" in SwitchResX and rebooting now gives me "3840x2160, 60Hz" in the P2415Q menu again for the Display Port input. Maybe there's a strange interaction when having both HDMI and DisplayPort inputs connected. I guess it doesn't matter, as long as you get an image with the expected resolution and refresh rate.

 

[EugW]

DisplayPort 4K timing (533 MHz pixel clock - same as CVT-RB timing) instead of HDMI 4K timing (594 MHz).

Is there a real world difference that we can see? I wasn’t aware of this technical difference.

 

[joevt]

Is there a real world difference that we can see? I wasn’t aware of this technical difference.

No big difference. I don't know why it's different. Basically, the HDMI timing has the same number of active pixels and refresh rate, they just add more pixels to the vertical (90, up from 62) and horizontal (560, up from 160) blanking period. Horizontal lines are drawn 1.5% faster (135 KHz vs 133 KHz) because there's 28 more total lines. Since the active lines are drawn faster, the vertical blank lasts 43% longer. This means the last line of a frame is displayed on screen longer before the first line is redrawn (0.66 ms, up from 0.46 ms; a frame is 16.66 ms). That might be useful but not noticeable.

My talk about how some Dell displays show 2160p instead of 3840*2160, 60Hz is just me complaining about the lack of info conveyed. The LG UltraFine displays sold by Apple are worse in that regard because they show zero info (no onscreen menus?). Remember old CRT displays that showed vertical and horizontal refresh rates? You might be able to query a display for vertical and horizontal refresh rates (and other info) using DDC/CI.

This onscreen info is useful to ensure you are getting the correct resolution and refresh rate. A problem in macOS is that you could be looking at a 5K frame buffer (looks like 2560x1440) but the computer might output a 4K signal (the 5K is scaled to 4K) to a 5K display, and there's nowhere in macOS that will show that problem unless you use an app like SwitchResX to view the timing info. iPad Pro probably doesn't tell you the timing info anywhere, right?

 

[EugW]

Unfortunately, there doesn't seem to be any documentation one way or the other on whether the display, or the iPad, can use DP 1.4. Apple only tells you what "just works" and I'm not sure the info on the LG site has been updated yet. So its anybody's guess. My guess is that all that has changed is the Thunderbolt controller & surrounding circuitry to allow USB-C DP Alt Mode operation.

I know that, in theory, the 2018/2019 15" MacBook Pros with discrete graphics definitely possibly might support DP 1.4, but I'm not sure if that has actually been confirmed.

This new Apple A2119 HDMI 2.0 adapter allows the USB-C iPad Pro, 2017 iMac,iMac Pro, and 2017 15” MacBook Pro to support simultaneous 4K 60 Hz HDR and USB 3.

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

Nothing about 5K (since it’s HDMI), but 4K 60 Hz + HDR10 + Dolby Vision along with that 5 Gbps USB 3 support would please a lot of people.

 

[loby]

This new Apple A2119 HDMI 2.0 adapter allows the USB-C iPad Pro, 2017 iMac,iMac Pro, and 2017 15” MacBook Pro to support simultaneous 4K 60 Hz HDR and USB 3.

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

Nothing about 5K (since it’s HDMI), but 4K 60 Hz + HDR10 + Dolby Vision along with that 5 Gbps USB 3 support would please a lot of people.

I was planning on buying this adapter a few weeks ago...glad I waited. Will work great with my MacBook Pro 2018!

 

[theluggage]

This new Apple A2119 HDMI 2.0 adapter allows the USB-C iPad Pro, 2017 iMac,iMac Pro, and 2017 15” MacBook Pro to support simultaneous 4K 60 Hz HDR and USB 3.

Read carefully: It has HDMI, USB-A and USB-C (data) ports that can be used simultaneously.

That doesn't mean that it can support 4K@60Hz HDMI and USB 3 (i.e. 5Gbps) simultaneously - its most likely that (like most other non-Thunderbolt USB-C multiport adapters on the market) the USB ports fall back to USB 2 480Kbps when a 4k@60Hz display is connected.

• Nearly all current USB-C-to-HDMI adapters consist of a DisplayPort-to-HDMI active converter using USB-C DisplayPort alt mode. I only say "nearly" because USB-C HDMI alt mode has been announced - maybe you know of a device that uses it.
• Using DisplayPort 1.2 at 4k@60Hz requires all 4 high-speed data lanes in a USB-C cable - leaving only the legacy USB-2 wires (USB 2 and USB 3 have always had separate wires) for data.
• DisplayPort 1.4 can support 4k@60Hz on 2 lanes and leave room for a USB3 connection, but...
• No Mac with only an Intel iGPU supports DP 1.4
• I'm pretty sure that no Mac with an Intel Thunderbolt controller prior to 2019 can support DP1.4 either (the bit I'm not sure about is whether this extends to "alt mode" as well - feel free to correct me if you have better info).

Is it possible that the new adapter supports simultaneous 4K 60 Hz HDR and USB 3 on (let's say) 2019 15" MBPs and iMacs that can support DP 1.4? I can't disprove it, but since that would be a major selling point over other adapters then they'd probably have highlighted it in the ad. As it is, when an ad so carefully avoids saying something there's usually a good reason.

 

[EugW]

Read carefully: It has HDMI, USB-A and USB-C (data) ports that can be used simultaneously.

That doesn't mean that it can support 4K@60Hz HDMI and USB 3 (i.e. 5Gbps) simultaneously - its most likely that (like most other non-Thunderbolt USB-C multiport adapters on the market) the USB ports fall back to USB 2 480Kbps when a 4k@60Hz display is connected.

• Nearly all current USB-C-to-HDMI adapters consist of a DisplayPort-to-HDMI active converter using USB-C DisplayPort alt mode. I only say "nearly" because USB-C HDMI alt mode has been announced - maybe you know of a device that uses it.
• Using DisplayPort 1.2 at 4k@60Hz requires all 4 high-speed data lanes in a USB-C cable - leaving only the legacy USB-2 wires (USB 2 and USB 3 have always had separate wires) for data.
• DisplayPort 1.4 can support 4k@60Hz on 2 lanes and leave room for a USB3 connection, but...
• No Mac with only an Intel iGPU supports DP 1.4
• I'm pretty sure that no Mac with an Intel Thunderbolt controller prior to 2019 can support DP1.4 either (the bit I'm not sure about is whether this extends to "alt mode" as well - feel free to correct me if you have better info).

Is it possible that the new adapter supports simultaneous 4K 60 Hz HDR and USB 3 on (let's say) 2019 15" MBPs and iMacs that can support DP 1.4? I can't disprove it, but since that would be a major selling point over other adapters then they'd probably have highlighted it in the ad. As it is, when an ad so carefully avoids saying something there's usually a good reason.

According to the specs of the adapter, only 2017+ 15" MacBook Pros and 2017+ iMacs and iMac Pros and 2018 iPad Pros can support 4K 60 Hz with this adapter. None of the Intel-only Macs can support 4K 60 Hz with this adapter. All those other Macs support only up to 4K 30 Hz. Actually, nothing is mentioned for 12" MacBook, but I assume that one can do 4K 30 Hz as well. (Elsewhere in the specs it says the 12" MacBook is supported, but it doesn't say at what resolution.)

Also, most non-Thunderbolt USB-C 4K + USB adapters do not fall back from 4Kp60 to 4Kp30 when USB 3 is attached. Usually they are only 4Kp60 plus USB 2 or else 4Kp30 plus USB 3, and that cannot change on the fly. If you plug in a USB 3 device into such a 4Kp60 adapter, you still only get USB 2, even if there is no monitor/TV attached at all. Usually the ones than can be changed, can only be changed though a firmware flash, which of course is totally impractical for regular use. So, what people do to get 4K 60 Hz over USB-C and USB 3 over USB C is to buy two separate adapters.

This new adapter appears to solve this problem, but only with 2017+ Macs with AMD graphics, and the 2018 iPad Pros.

 

[joevt]

A Mac needs Titan Ridge and AMD graphics to support DisplayPort 1.4. I don't think the iMac Pro has Titan Ridge, so it must be using 4 lanes of DisplayPort 1.2. But other Macs have DisplayPort 1.2, so there's no reason they should be limited to 4K 30 Hz. This might be a case where pixel clock patch can be used.

Back to the new LG UltraFine 5K display, a reader on eGPU.io was able to use a Moshi DisplayPort to USB-C cable to get 4K. I think this is a better result than the LG UltraFine 4K which required a USB 2.0 signal with the DisplayPort signal which can be obtained using a Huawei VR 2 cable (USB 2 + DisplayPort 1.2 to USB-C cable).
https://egpu.io/forums/gpu-monitor-...hat-can-power-the-lg-ultrafine-5k/#post-63522
https://egpu.io/forums/gpu-monitor-...y-to-drive-lg-ultrafine-4k-monitor-with-egpu/
https://egpu.io/forums/gpu-monitor-peripherals/lg-ultrafine-5k-now-usb-c-powered/
#140

 

[theluggage]

According to the specs of the adapter, only 2017+ 15" MacBook Pros and 2017+ iMacs and iMac Pros and 2018 iPad Pros can support 4K 60 Hz with this adapter.

Well, that's moot for 2017 iMacs and 2018 iPads, since the older models of those didn't have USB-C at all...

As for MBPs, its the 2017 cut-off that suggests this isn't DP1.4 - There's been no suggestion that MBPs pre-2018 support DP1.4. There was some change in the DisplayPort/USB-C implementation in 2017 - I remember that a bunch of older video adapters stopped working - but I dont think it was DP1.4.

Usually they are only 4Kp60 plus USB 2 or else 4Kp30 plus USB 3, and that cannot change on the fly.

Possibly, then, its exactly that ability to adapt 'on-the-fly' that introduce the 2017 cut-off (and Mojave requirement).

A Mac needs Titan Ridge and AMD graphics to support DisplayPort 1.4.

That's what I assume. The only possible chink is that maybe it only applies to Thunderbolt mode - where the DisplayPort data has to be moshed together with PCIe - and not to USB-C DisplayPort Alt Mode - where the DP signals are simply routed to wires in the USB-C cable. However, I've never seen any suggestion that 2017 Macs can do this. Any motherboard designers in the house?

 

[EugW]

Well, that's moot for 2017 iMacs and 2018 iPads, since the older models of those didn't have USB-C at all...

As for MBPs, its the 2017 cut-off that suggests this isn't DP1.4 - There's been no suggestion that MBPs pre-2018 support DP1.4. There was some change in the DisplayPort/USB-C implementation in 2017 - I remember that a bunch of older video adapters stopped working - but I dont think it was DP1.4.

2016 MBP not supported for 4K 60 Hz with this particular adapter as you know. More importantly though, none of the 12” MacBooks, including the 2017, are supported for 4K 60 Hz with this adapter.

Yes 2017 changed something with USB-C but USB-C adapters that support 4K 60 Hz on the 2017 iMac also work fine on the 2017 12” MacBook as well as other older Macs at 4K 60 Hz.

Possibly, then, its exactly that ability to adapt 'on-the-fly' that introduce the 2017 cut-off (and Mojave requirement).

Possibly, but based on what?

That's what I assume. The only possible chink is that maybe it only applies to Thunderbolt mode

This is not a Thunderbolt adapter.

 

[joevt]

That's what I assume. The only possible chink is that maybe it only applies to Thunderbolt mode - where the DisplayPort data has to be moshed together with PCIe - and not to USB-C DisplayPort Alt Mode - where the DP signals are simply routed to wires in the USB-C cable. However, I've never seen any suggestion that 2017 Macs can do this. Any motherboard designers in the house?

I tried piping DisplayPort 1.4 through a Sunix UPD2018 during testing of the DisplayPort 1.4 MST hub in the HP Thunderbolt Dock G2. Didn't work. Doesn't mean it can't happen with an Alpine Ridge. I suppose you can do anything with a PCB and enough bits to make it work. I mean, Apple did something to make iMacs be able to take DisplayPort inputs through their DisplayPort outputs to make Target Display Mode. They also somehow are able to distribute two DisplayPort signals among 4 DisplayPort inputs of two Thunderbolt controllers in the Mac mini 2018. And I'm sure they've done some weird stuff with the new 2019 Mac Pro thunderbolt stuff and graphics cards.

The best way to know for sure what this adapter does is get one and dump the dpcd to see the link speed and width. Too bad Apple doesn't show this info for DisplayPort like they do for PCIe and Thunderbolt in System Information.app. DisplayPort has a topology like Thunderbolt and PCIe (For example, Intel Graphics Control Panel in Windows shows MST hub and displays connected to a MST hub).

 

[joevt]

According to the specs of the adapter, only 2017+ 15" MacBook Pros and 2017+ iMacs and iMac Pros and 2018 iPad Pros can support 4K 60 Hz with this adapter. None of the Intel-only Macs can support 4K 60 Hz with this adapter. All those other Macs support only up to 4K 30 Hz. Actually, nothing is mentioned for 12" MacBook, but I assume that one can do 4K 30 Hz as well. (Elsewhere in the specs it says the 12" MacBook is supported, but it doesn't say at what resolution.)

Also, most non-Thunderbolt USB-C 4K + USB adapters do not fall back from 4Kp60 to 4Kp30 when USB 3 is attached. Usually they are only 4Kp60 plus USB 2 or else 4Kp30 plus USB 3, and that cannot change on the fly. If you plug in a USB 3 device into such a 4Kp60 adapter, you still only get USB 2, even if there is no monitor/TV attached at all. Usually the ones than can be changed, can only be changed though a firmware flash, which of course is totally impractical for regular use. So, what people do to get 4K 60 Hz over USB-C and USB 3 over USB C is to buy two separate adapters.

This new adapter appears to solve this problem, but only with 2017+ Macs with AMD graphics, and the 2018 iPad Pros.

I tried the new adapter. It appears to be two lanes of DisplayPort 1.4 or DisplayPort 1.2 according to the info in the DPCD registers that you can see with the following command:

/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > ~/Documents/AGDCDiagnose_a.txt 2>&1

Therefore, my Mac mini 2018 (and a MacBook I tried) can only go up to 3840x2160 30Hz. I tried connecting the adapter to the USB-C DisplayPort alt mode port of an HP Thunderbolt Dock G2 which has a DisplayPort 1.4 MST hub internally, hoping that the hub could convert 4 lanes of DisplayPort 1.2 to 2 lanes of DisplayPort 1.4 to get 3840x2160 60Hz. I was able to select that resolution but my Dell 4K displays with HDMI 2.0 inputs would only flash occasionally.

The USB port is limited to 5 Gbps. This USB 3.x speed means only two lanes is available for DisplayPort to HDMI conversion. If the adapter was limited to USB 2.0, then we could have used all 4 lanes. A pixel clock patch cannot help with the limitations imposed by having only two lanes on DisplayPort 1.2 output.

I haven't tried the adapter with a DisplayPort 1.4 source yet.

I had problems using a bus powered USB 3.1 gen 2 drive (Plugable USB-C NVMe based on JMicron JMS583) - reads or writes would hang. A USB 3.0 hard drive worked without problem.

 

[EugW]

Someone has posted that they get 2160p60 with a 2018 iPad Pro and with a 2018 15” MacBook Pro.

However, they did not try simultaneous USB 3.

Note though for the 15” MBP, they had to manually select the scaled resolution setting to get 2160p60 because for some reason it otherwise would get limited to 2160p30.

 

[Dandu]

I have tried with a 2017 15" MacBook Pro : it works with USB 3.0 and 2160p60

I have connected to a Nvidia card under Windows (on a classic PC), and the bitrate for DP is 8.1 Gb/s (2 lanes), so DP 1.3 or 1.4 (and only 5.4 with the old adapter).

 

[EugW]

I have tried with a 2017 15" MacBook Pro : it works with USB 3.0 and 2160p60

I have connected to a Nvidia card under Windows (on a classic PC), and the bitrate for DP is 8.1 Gb/s (2 lanes), so DP 1.3 or 1.4 (and only 5.4 with the old adapter).

Sweet! DisplayPort 1.4 confirmed for 2017 Macs with AMD dGPUs using this adapter.

Now I hold out faint hope that some 2017 Macs will support 4K iTunes streaming. However, Apple specifically said 2018 Macs or later are required.

 

[joevt]

Someone has posted that they get 2160p60 with a 2018 iPad Pro and with a 2018 15” MacBook Pro.

Note though for the 15” MBP, they had to manually select the scaled resolution setting to get 2160p60 because for some reason it otherwise would get limited to 2160p30.

Where does it say the resolution on an iPad Pro? On a Mac, you need to looking at the timing info using SwitchResX to be sure. Nowhere else in macOS does it say the output signal timing.

I have tried with a 2017 15" MacBook Pro : it works with USB 3.0 and 2160p60
I have connected to a Nvidia card under Windows (on a classic PC), and the bitrate for DP is 8.1 Gb/s (2 lanes), so DP 1.3 or 1.4 (and only 5.4 with the old adapter).

Where does it say the DisplayPort bit rate and lanes in Windows?

 

[EugW]

Where does it say the resolution on an iPad Pro?

You just look on the display of course.

Many displays (esp. TVs) will indicate the resolution and refresh rate.

 

[joevt]

You just look on the display of course.

Many displays (esp. TVs) will indicate the resolution and refresh rate.

Oh, of course. I was thinking about the LG displays that Apple sells that don't have any onscreen menu info like that.

What about the case for Windows? Which display was used that shows DisplayPort bit rate and lanes? I have some Dell displays that only show resolution and refresh rate (except when it says something useless like 2160p or 1080p where the refresh rate could be 30 or 60 Hz).

For people that don't have DisplayPort 1.4, or have a DisplayPort 1.4 GPU behind an Alpine Ridge, then any four lane adapter based on the MCDP2900 should work to provide 4K 60 Hz HDMI. You probably need a DisplayPort 1.4 source for the MCDP2900 to produce HDR since HDR is not a feature of DisplayPort 1.2. The MCDP2900 only requires HBR2 (DisplayPort 1.2 speed) so maybe Alpine Ridge will allow DisplayPort 1.4 at that speed from the GPU (probably not - but maybe - since the Thunderbolt controller doesn't need to know anything about the signal if it is output via DisplayPort alt mode instead of Thunderbolt?).

Since the MCDP2900 maxes out at 5.4 Gbps, then it means the Apple Adapter is using a different chip. Maybe the PS186. The output from AGDCDiagnose does not give a clue here. The OUI is Apple. The Adapter has name "cHDMIb". The 2018 Mac Mini's HDMI 2.0 port has name "pHDMIf". The iFixit teardown says the 2018 Mac Mini uses a MCDP2920A4 but I can't find info on that chip (maybe it's in the same family as the MCDP2900).

The Apple adapter has a two port USB 2.0 hub, one port is for the type-A connector and the other port is for the USB billboard device. This is normal for USB-C adapters. The USB 3.0 hub has one port for the type-A connector. Both hubs have the same serial number. the Hubs have vendor "Apple Inc." and version "40.09".

 

[joevt]

I still don't understand how iMac Pro can support 4K 60Hz with the new adapter. Everything I've read (including the iFixit teardown) says that the iMac Pro contains Alpine Ridge controllers. Did Apple implement a USB-C alt mode pass through that bypasses the Alpine Ridge controllers?