LG UltraFine 5K Build

[didierM4E]

- MacBook Pro 2016 2,9Ghz Radeon Pro 460 High Sierra Beta 8
- Akitio Node Thunderbolt 3
- Une Radeon Vega 64 8GB
- LG Ultrafine 5k

I plugged the 2 cables on the Alpine Ridge and the single thunderbolt from the display...

i'll try with other configurations (like LG USB C etc.)

 

[joevt]

- MacBook Pro 2016 2,9Ghz Radeon Pro 460 High Sierra Beta 8
- Akitio Node Thunderbolt 3
- Une Radeon Vega 64 8GB
- LG Ultrafine 5k

I plugged the 2 cables on the Alpine Ridge and the single thunderbolt from the display...

i'll try with other configurations (like LG USB C etc.)

Where's the GC-ALPINE RIDGE? Is the Radeon Vega 64 in the Akitio node working with normal displays?

 

[didierM4E]

I tried the alpine ridge outside of the Akitio, plugged only on the Vega GPU.
The Akitio is working well with HDMI or DP monitor, yes.

 

[joevt]

I tried the alpine ridge outside of the Akitio, plugged only on the Vega GPU.
The Akitio is working well with HDMI or DP monitor, yes.

The GC-ALPINE RIDGE needs power from a powered PCIe slot, but the PCIe slot does not need to be connected to a computer. For this I used a IT-GO "ADP-099-31" as pictured at #74. It has two PCIe x16 slots (electrically PCIe 2.0 x1) powered by an external power supply.

I had previously tried a PCIe x1 to x16 riser but the GC-ALPINE RIDGE ridge card wouldn't start transmitting video over Thunderbolt 3 unless the riser was connected to a computer's PCIe slot. With the IT-GO "ADP-099-31", I do not have that problem.

 

[joevt]

I tried the alpine ridge outside of the Akitio, plugged only on the Vega GPU.

If you don't have an externally powered PCIe slot for the GC-ALPINE RIDGE, then you could put it in a computer that has a spare PCIe slot (It doesn't need to be in a slot that supports a Thunderbolt add-in card).

Another thing you can try is putting the GC-ALPINE RIDGE in the Akitio, and connect two USB-C to mini DisplayPort cables to the GC-ALPINE RIDGE from the MacBook Pro and see if the LG 5K works from the GC-ALPINE RIDGE instead of directly from the MacBook Pro. Try this first without connecting the Akitio to the MacBook Pro. If that doesn't work then try connecting the Akitio to the MacBook Pro.

The IT-GO is like an Akitio, except it is much less expensive, since it only supports PCIe 2.0 x1. It connects directly to a computer's PCIe slot using a USB 3.0 cable.

 

[Briax]

Hi @joevt

Can you confirm/clearify if this setup will work based on your experience:

I'll be using a MacBook Pro 2016 (460 4GB).

2 x Alpine Ridge controllers in externally powered PCIe slots, connected to a Vega 64 GPU in a an external GPU enclosure like the Akitio Node. 2 x 5k Ultrafine displays, each one powered by a TB3 connection on their separate Alpine Ridge Controller.
Will this work?

Best regards

 

[joevt]

Hi @joevt

Can you confirm/clearify if this setup will work based on your experience:

I'll be using a MacBook Pro 2016 (460 4GB).

2 x Alpine Ridge controllers in an externally powered PCIe slots, connected to a Vega 64 GPU in a an external GPU enclosure like the Akitio Node. 2 x 5k Ultrafine displays, each one powered by a TB3 connected on their separate Alpine Ridge Controller.
Will this work?

I think so. But remember you won't be able to use the display's speakers, camera, or USB ports. And you have to use an app that transmits DDC/CI to change brightness.

I've only tested the following: Nvidia Titan X, GA-Z170X-Gaming 7, IT-GO "ADP-099-31", 2x GC-ALPINE RIDGE, Startech Thunderbolt 3 to Dual DisplayPort adapter, Dell UP2715K. Some PCIe risers do not work (I tried 1x to 16x) unless you connect them to a computer's PCIe slot. The IT-GO is a 1x to dual 16x and doesn't have that problem.

dnetcrawler was able to use two LG 5K (but one was less than 5K resolution) with a AMD Radeon VEGA Frontier Edition, ASUS X99 Rampage V Edition 10, 2x GC-ALPINE RIDGE (one connected to Thunderbolt add-in card header but this is optional).
#193

The AMD cards usually only have 3 DisplayPort outputs. To run both displays at 5K, you need 4 DisplayPort outputs. You could supply one of the GC-ALPINE RIDGE cards with DisplayPort outputs from your MacBook Pro using two USB-C to mini DisplayPort cables, but you gain nothing from just using the MacBook Pro's Thunderbolt 3 port instead. If the DisplayPort outputs of the Vega support DisplayPort 1.3, then maybe you can use a DisplayPort 1.3 or 1.4 MST hub to get two DisplayPort 1.2 outputs? I've never seen it and I don't know if it's possible. I don't think such hubs exist yet. A DisplayPort 1.2 MST hub is not sufficient since it doesn't have bandwidth for two 4K@60Hz streams (actually, only two 2560x2880@60Hz streams is required but that's still too much for DisplayPort 1.2).

There are some AMD cards with 4 or 6 DisplayPort outputs. I don't know their price, compatibility, or performance compared to the Vega.

There's no way to convert HDMI 2.0 to DisplayPort 1.2 4K@60Hz yet so that's not an option.

 

[Briax]

arify if this setup will work based on your experience:

I think so. But remember you won't be able to use the display's speakers, camera, or USB ports. And you have to use an app that transmits DDC/CI to change brightness.

I've only tested the following: Nvidia Titan X, GA-Z170X-Gaming 7, IT-GO "ADP-099-31", 2x GC-ALPINE RIDGE, Startech Thunderbolt 3 to Dual DisplayPort adapter, Dell UP2715K. Some PCIe risers do not work (I tried 1x to 16x) unless you connect them to a computer's PCIe slot. The IT-GO is a 1x to dual 16x and doesn't have that problem.

dnetcrawler was able to use two LG 5K (but one was less than 5K resolution) with a AMD Radeon VEGA Frontier Edition, ASUS X99 Rampage V Edition 10, 2x GC-ALPINE RIDGE (one connected to Thunderbolt add-in card header but this is optional).
#193

The AMD cards usually only have 3 DisplayPort outputs. To run both displays at 5K, you need 4 DisplayPort outputs. You could supply one of the GC-ALPINE RIDGE cards with DisplayPort outputs from your MacBook Pro using two USB-C to mini DisplayPort cables, but you gain nothing from just using the MacBook Pro's Thunderbolt 3 port instead. If the DisplayPort outputs of the Vega support DisplayPort 1.3, then maybe you can use a DisplayPort 1.3 or 1.4 MST hub to get two DisplayPort 1.2 outputs? I've never seen it and I don't know if it's possible. I don't think such hubs exist yet. A DisplayPort 1.2 MST hub is not sufficient since it doesn't have bandwidth for two 4K@60Hz streams (actually, only two 2560x2880@60Hz streams is required but that's still too much for DisplayPort 1.2).

There are some AMD cards with 4 or 6 DisplayPort outputs. I don't know their price, compatibility, or performance compared to the Vega.

There's no way to convert HDMI 2.0 to DisplayPort 1.2 4K@60Hz yet so that's not an option.

Hi again,

Thank you very much for the lengthy and detailed reply, really appreciate it man.

So it sounds like I am loosing quite a bit of functionality going this route.

Do you know if it's possible using the eGPU and pipe it back through the Mac and use the LG Ultrafines directly connected to the Mac, but using the power of the eGPU?

Best regards

 

[joevt]

Thank you very much for the lengthy and detailed reply, really appreciate it man.

So it sounds like I am loosing quite a bit of functionality going this route.

Do you know if it's possible using the eGPU and pipe it back through the Mac and use the LG Ultrafines directly connected to the Mac, but using the power of the eGPU?

Best regards

I think this could work but there's a performance penalty to consider. Read these:
https://egpu.io/how-to-egpu-accelerated-internal-display-macos/
https://egpu.io/setup-guide-external-graphics-card-mac/

You need a headless adapter for each display you want to make on the eGPU. I suppose you could make up to 6 displays with an MST 1.2 hub (you can connect up to 3 hubs). It doesn't matter the size of the fake display since the frame buffer can be independent from the screen resolution. Use SwitchResX to make a 5K scaled resolution for each display. Then you can run Spectacle to move an eGPU window to one of your displays (I think it just moves the window, so the OS has to draw it on the Mac connected display by copying the contents from the eGPU context to the MacBook Pro's GPU context). If there's a problem, then you can ask the author to make a fix for your situation. It's also open source.

Thunderbolt 3 has a bandwidth limitation of 40 Gbps. Only 22 Gbps can be used for PCIe communication.
Read page 6 of the Thunderbolt 3 technology brief:
https://thunderbolttechnology.net/sites/default/files/Thunderbolt3_TechBrief_FINAL.pdf

To send 5K at 60 Hz using DisplayPort over Thunderbolt requires 22 Gbps coincidentally but that doesn't matter since your Mac is not sending a DisplayPort stream over Thunderbolt to the eGPU. I believe the frame buffer is copied from the eGPU to the Mac's frame buffer using PCIe, not DisplayPort, so the DisplayPort bandwidth doesn't matter. The PCIe bandwidth required for 5120 x 2880 x 60 fps x 3 bytes per pixel x 8 bits per byte might be just 19.77 Gbps so you might get 60 fps for one display at most or less than that if it tries to copy 4 bytes per pixel (26.36 Gbps).

The MacBook Pro 2016 can support only 2 LG 5K displays. Each additional LG 5K display will need to be powered by an eGPU using two DisplayPort 1.2 connections and a GC-ALPINE RIDGE card to convert that to dual DisplayPort stream over Thunderbolt.

The AMD Radeon 7870 graphics card is old but may have 6 mini DisplayPort connections. The Radeon E8870 is newer but not as powerful? The Radeon E9260 is newer still but only has 4 DisplayPorts which might be enough for you anyway. I don't know where to buy those last two.

 

[Briax]

Again mate, thank you very much for taking the time to explain!

I think I'll sit tight now for.. at least till High Sierra is out with native eGPU support.

It's a lot of money to drop on something that might/might not work.. haha

Cheers mate!