Getting to a single cable with LG 27” TB3 display
Clear all

Getting to a single cable with LG 27” TB3 display  


New Member
Joined: 2 years ago

I recently when down the eGPU route to get to triple displays on a MBP 2018, and it’s been great.

I’ve ended up with a Razer Core X (non-chroma),driving two displays, and a LG 27” 5K TB3 display connected directly to the MBP. It’s working great. But I’m still pining for the single-cable life.

Looking around, I see there are very few options. Well, basically one: Find a eGPU enclosure with two PCIe slots. And looking at the list — there aren’t any good ones.

As I’ve looked around, I don’t hold out much hope. However, today I came across the HighPoint RocketStore TB3 enclosure which has an upstream TB3 port and an available PCIe slot. Does this mean I could throw in an Alpine Ridge TB3 card into it, connect it’s DisplayPort input from a DisplayPort output on my actual GPU, and bobs-your-uncle?


MBP->HighPoint->CoreX->[Display A, Display B]
      |          |
      |--AlpineRidge->LG TB3 Display

Would that work?

Looking at the power output of the HighPoint, it looks like a nope, because it can’t supply the power to the laptop, so it’s going to be single cable.

Am I out of luck?

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.


Illustrious Member Admin
Joined: 4 years ago

@grork, It's not advisable to place the eGPU in a daisy chain. There's another possibility of using a single Thunderbolt 3 cable but the Razer Core X needs to come out of the equation. Using an two-TB3-port enclosure such as AKiTiO Node Pro, you can charge the laptop (60W PD), eGPU in the PCIe slot running two power two displays, and Thunderbolt 3 monitor passthrough via the second TB3 downstream port. The LG 5K UltraFine in this configuration would run off the iGPU/dGPU not the eGPU.


external graphics card builds
best laptops for external GPU
eGPU enclosure buyer's guide

2013 Mac Pro (FP D500 x2) [3rd,12C,E] + RX 5700 XT @ 16Gbps-TB2>TB3 (Mantiz Saturn Pro) + macOS 11 [build link]  

Noble Member
Joined: 3 years ago

The OWC Helios 3S has 85W of PD.

For best performance, you want the eGPU to be first in the chain so maybe move the GPU to the OWC (you'll need a riser and PSU to be able to connect the eGPU  - I've used a PCIe to M.2 adapter with a ADT M.2 to PCIe cable connected to that) and put the Alpine Ridge in the Razer Core X (or another Helios 3S or a Sonnet Echo Express or a Highpoint or Netstor or whatever you like). The HighPoint has a nice compact size for full height PCIe cards.

The Sonnet Echo Express SE IIIe has 100W of power delivery and 3 slots. You'll need a riser and PSU for a GPU but it costs more than twice as much as the other options. You could connect two LG Ultrafine 5K displays if your GPU had 4 DisplayPort outputs.

You know that currently an Alpine Ridge connected externally like this won't give all the features of the Thunderbolt displays, right? And there may be other issues.

As @itsage said, connecting a LG UltraFine 5K to the downstream of a Thunderbolt expansion box like the AKiTiO, Sonnet, OWC, Highpoint, etc. will work and it will give you all the features without having to use the Alpine Ridge. It will be powered by the GPU of the MBP in that case. It will also reduce the H2D bandwidth of the eGPU since you're adding DisplayPort to the Thunderbolt chain instead of bypassing the Thunderbolt chain and using the eGPU to power the display in the case of the Alpine Ridge solution.

This post was modified 2 weeks ago

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case