LG UltraFine 5K Build

[buyjoey]

The MacBook Pro has two Thunderbolt controllers, one on each side. Each takes two DisplayPort inputs from the AMD graphics controller. So each side can have two 4K displays or one 5K Dual Link SST display. The MacBook Pro tech specs don't mention DisplayPort 1.4 support, so it's unclear whether a single Titan Ridge controller in a MacBook Pro can output to two 5K displays - one per port - if the 5K displays use DisplayPort 1.4.

The LG 34WK95U-W display is a 34 inch 5K2K UltraWide display (less vertical pixels than the LG UltraFine 5K display). It supports both DisplayPort 1.4 and Dual Link SST DisplayPort 1.2 over Thunderbolt connections. The Thunderbolt connection may also support DisplayPort 1.4. It gets confusing - enough that macOS doesn't support the Thunderbolt connection on the MacBook Pro 2018 properly. There are other 5K DisplayPort 1.4 displays.

Hi, @joevt. Thanks for your info.

I have Vega 64 with three DP1.4 ports.
From what I understand, Titan Ridge's DP port is 1.4 as well.

On each DP port I can get up to 8K resolution.
So, if I have two Vega 64, it would be possible to use two LG 5K?

 

[joevt]

I have Vega 64 with three DP1.4 ports.
From what I understand, Titan Ridge's DP port is 1.4 as well.

On each DP port I can get up to 8K resolution.
So, if I have two Vega 64, it would be possible to use two LG 5K?

Titan Ridge supports DisplayPort 1.4 and each port can support one 8K display (8K30Hz without Display Stream Compression, 60Hz with DSC). This depends on the graphics card connected to the Titan Ridge (Intel graphics only supports DisplayPort 1.2 but AMD and Nvidia should support DisplayPort 1.4 but that depends on the graphics drivers).

An LG UltraFine 5K display requires two DisplayPort 1.2 connections over Thunderbolt 3 for 5120x2880 so one per Vega 64 card (unless it has more than 3 DisplayPort ports).

An LG 34WK95U-W requires two DisplayPort 1.2 connections over Thunderbolt 3 for 5120x2160 but it should also allow the same resolution with a single DisplayPort 1.4 connection so one Vega 64 should be able to control three of them if it has three DisplayPort 1.4 ports.

If it doesn't work then there's a problem with the drivers.

 

[luckyal]

Titan Ridge supports DisplayPort 1.4 and each port can support one 8K display (8K30Hz without Display Stream Compression, 60Hz with DSC). This depends on the graphics card connected to the Titan Ridge (Intel graphics only supports DisplayPort 1.2 but AMD and Nvidia should support DisplayPort 1.4 but that depends on the graphics drivers).

An LG UltraFine 5K display requires two DisplayPort 1.2 connections over Thunderbolt 3 for 5120x2880 so one per Vega 64 card (unless it has more than 3 DisplayPort ports).

An LG 34WK95U-W requires two DisplayPort 1.2 connections over Thunderbolt 3 for 5120x2160 but it should also allow the same resolution with a single DisplayPort 1.4 connection so one Vega 64 should be able to control three of them if it has three DisplayPort 1.4 ports.

If it doesn't work then there's a problem with the drivers.

Hey @joevt do you mind taking a look at this thread you contributed to before? I understand if you had moved on.

 

[bluepr0]

Just discovered that with the Gigabyte Designare you can have one LG Ultrafine 5k working perfectly out of the box. Hopefully we get soon a motherboard with 2 DPI in ports so we can output 2x 5k displays . Looking forward to that new Apple Pro cinema display which is 99.999% probably to be TB3.

 

[madlitch]

Just discovered that with the Gigabyte Designare you can have one LG Ultrafine 5k working perfectly out of the box. Hopefully we get soon a motherboard with 2 DPI in ports so we can output 2x 5k displays . Looking forward to that new Apple Pro cinema display which is 99.999% probably to be TB3.

@bluepr0
Are you sure it's running at full resolution? It shouldn't work with a single displayport 1.4 output, as the monitor was designed to have two dp 1.2 inputs over thunderbolt 3. It might be running at just over 4k @ 4096x2304. Either double check in windows, open up System Information>Graphics/Displays, or download SwitchResX at http://www.madrau.com/.

In SwitchResX, it should say 2560x1440 HiDPI, which is what the UI is running at, but practically doubled. Same thing in System Information, it should say 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus) under 'Resolution', and 2560x1440 under 'UI Looks Like'.

 

[bluepr0]

@bluepr0
Are you sure it's running at full resolution? It shouldn't work with a single displayport 1.4 output, as the monitor was designed to have two dp 1.2 inputs over thunderbolt 3. It might be running at just over 4k @ 4096x2304. Either double check in windows, open up System Information>Graphics/Displays, or download SwitchResX at http://www.madrau.com/.

In SwitchResX, it should say 2560x1440 HiDPI, which is what the UI is running at, but practically doubled. Same thing in System Information, it should say 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus) under 'Resolution', and 2560x1440 under 'UI Looks Like'.

Sorry I didn’t explain. You connect your DP out of your GPU with the DP IN of your Mobo and then connect your TB3 device in the TB3 USBC out of the mobo

 

[madlitch]

Sorry I didn’t explain. You connect your DP out of your GPU with the DP IN of your Mobo and then connect your TB3 device in the TB3 USBC out of the mobo

I'm aware, I was considering buying a designare to support this monitor, but it wouldn't have worked at full resolution like it would if you used a dedicated gc alpine ridge or gc titan ridge card. The TB3 aspect of the monitor will work fine, as in the microphone, camera, and USB bank, but the monitor won't accept anything more than 4096x2304 (I think that's the max resolution for 1.2, might be 3840x2600) if you're only using one displayport cable. The monitor does not support DP 1.4, which can handle 5k@60fps. DP 1.2 can't handle 5k, that's why Apple implemented a controller that works like the GC expansion cards to funnel two DP 1.2 streams through TB3 on the latest MacBook Pros.

 

[bluepr0]

I'm aware, I was considering buying a designare to support this monitor, but it wouldn't have worked at full resolution like it would if you used a dedicated gc alpine ridge or gc titan ridge card. The TB3 aspect of the monitor will work fine, as in the microphone, camera, and USB bank, but the monitor won't accept anything more than 4096x2304 (I think that's the max resolution for 1.2, might be 3840x2600) if you're only using one displayport cable. The monitor does not support DP 1.4, which can handle 5k@60fps. DP 1.2 can't handle 5k, that's why Apple implemented a controller that works like the GC expansion cards to funnel two DP 1.2 streams through TB3 on the latest MacBook Pros.

ah damn, I thought the TB3 built in card will just figure it out internally :/

 

[tonyarnold]

I can confirm, having tried this myself with a Titan Ridge card in my build. The DP 1.4 cable doesn't send anything to the LG Ultrafine 5K display. You need the two DP 1.2 cables for it to function properly.

 

[tholstro]

I have a LG UF 5K working at full resolution over TB3 with RX580 plugged into the Designare MOBO DisplayPort in... No Titan Ridge adapter required but that works well too!

I just purchased the little brother LG UF 4K and not sure at this point how to get it working. It's listed as a USBC monitor but like the 5K it's actually DisplayPort.