eGPU won't output to monitors: LG Ultrafine 4k
 
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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 

Hey everyone, 

I'm Jonathan. New here. Hello. Sorry to join and be an immediate drain on your expertise, but yea, I need you.

Hardware set up for the avoidance of doubt:

MacMini 2018 3.2GHz, 6 core i7 64GB Ram

2x4k LG Ultrafine monitors

Razer Core X Chroma enclosure

Sapphire Nitro AMD 5700XT card

 

I know the best results will be gained when I connect my monitors to the eGPU and I've tried this, but they won't spark to life. Just black screen. This is true if I live switch (from the Mac mini directly) when the system is up and running or if I attempt to boot with the eGPU plugged in. I've got two DP to USB-C cables for this purpose.

So, the big questions:

1. I've read elsewhere that the LG 4K monitors are troublesome because they're thunderbolt and that a specific cable might be needed? Thoughts?

2. Is there any point to the eGPU if I don't connect the monitors? 

3. Is the best way out of this hole to return the eGPU or invest in monitors Smile (I'm in so deep, it's hard to tell)

J

 

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

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Eightarmedpet
(@eightarmedpet)
Noble Member Moderator
Joined: 4 years ago
 

Ha, welcome aboard Jonathan!

The 4K Ultrafines can also be powered with a DP to USB C cable - what cable are you using atm? There are a few posts on here about that if you can do some digging.

IIRC the best option is a VR cable which also has USB A which means you keep all functionality of the monitors (ports and brightness etc).

Whats your use case? Because depending on what you are using the eGPU for you can just set "prefer egpu" option in the "get info" pane for an app.

 

A copy and past from the far smarter than me @joevt 

"The Belkin or Huawei VR 2 cables might be the cheapest option currently.
https://egpu.io/forums/gpu-monitor-peripherals/does-a-usb-c-monitor-support-displayport-input-over-a-usb-c-to-displayport-cable/paged/4/#post-79127 "

 

This post was modified 3 months ago

2017 13" MacBook Pro Touch Bar
GTX1060 + AKiTiO Thunder3 + Win10
GTX1070 + Sonnet Breakaway Box + Win10
GTX1070 + Razer Core V1 + Win10
Vega 56 + Razer Core V1 + macOS + Win10
Vega 56 + Mantiz Venus + macOS + W10

---

LG 5K Ultrafine flickering issue fix

 
2017 13" MacBook Pro [7th,2C,U] + RX 5700 XT @ 32Gbps-TB3 (Mantiz Venus) + macOS 10.15.4 & Win10 2004 [build link]  


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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 

Hi, and thanks!

So I’m a webinar producer amongst other things, so I do live broadcasts from my Mac mini. I’m using eCamm live for that which, when combined with software like Microsoft Teams is GPU heavy (and my Mac mini is obviously lacking). Hence the eGPU. 

I’ve seen a few recommendations for that Moshi cable. I’d bought 2 other DisplayPort > USB-C cables from Amazon but they didn’t work at all. I guess (?) they weren’t bidirectional which appears to be a necessity. 

Ever feel like you’re in a tech swamp where the only solution is to throw more £/$ at it? That’s where I’m at... 

I’ve just bit buy on two of those Moshi cables — fingers crossed that solves it.

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

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corb555
(@corb555)
Active Member
Joined: 5 months ago
 

@jonathan_phillips, I have the LG Ultrafine 5k on an eGPU.  The thing that makes these monitors a pain is that they don't have a power switch and instead use some signal from the USB-C connection to determine when to power on.  The Moshi cables should work from a video standpoint since they're bi-directional, but they may not pass whatever sequence is needed to turn on the LG.  If they work - great!  If they don't work, you may need to do what I did - I added an HDMI monitor directly to the Mini.  The system boots with the HDMI monitor and this wakes up the eGPU which then wakes up the LG.  The third monitor can be any cheapo HDMI and is ONLY used for booting - no apps since it's not connected to the eGPU and any app on it would not get eGPU acceleration.

Also, once you get the monitors working, be sure to go to Info on the apps you use and set them to "prefer external GPU"

 

2019 13" MacBook Pro [8th,4C,U] + RP W5700 @ 32Gbps-TB3 (AKiTiO Node Titan) + macOS 10.15.4 [build link]  

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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 

Ah, ok, that’s extremely helpful. In summary, it’s the LG architecture (switch on prompted by the Mac) that causes this issue.

Cables arrive tomorrow so I’ll give that a go. I have a spare HDMI monitor (ok, it’s a cheap small TV) so I’ll try that suggestion, thank you. I presume from your comment that the system holds steady assuming you don’t shut down? Do I have to repeat if the Mac goes to sleep for example?

Failing that, I might sell my 2x LG 4K and buy a DP monitor that has a on/off button - that seems a whole heap easier!

Glad of your help. I’ve been slowly going crazy over this one - thought I was losing the tech touch!

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

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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 

The Moshi cable arrived today and no joy -- it just won't kick start the LG 4k ultrafines, even with your HDMI monitor option. 

Just so I don't give up at the last hurdle, you say "The system boots with the HDMI monitor and this wakes up the eGPU which then wakes up the LG". Can you explain 'wakes up the eGPU' because mine (the Razer X Chroma) is either on/off ... doesn't appear to 'wake' on boot?

I think I've drawn a blank on this otherwise. 

Final options:

Return the eGPU and card and forget this happened
Buy new DP monitors that just don't have this LG design-enabled problem

 

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

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joevt
(@joevt)
Noble Member
Joined: 3 years ago
 

@jonathan_phillips, to be clear which LG UltraFine 4K displays do you have? The new 24" Thunderbolt/USB-C display or the older 22" USB-C display? I believe the Moshi should work with the new displays but not the old ones. The Alogic cable may work with the old displays. You would get better results/more features with one of the solutions that includes USB.

 

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


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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 

The older 4ks - they’re 2017 vintages. 

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

.

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joevt
(@joevt)
Noble Member
Joined: 3 years ago
 

@jonathan_phillips, Did you try the Alogic cable? Otherwise you need USB for those.

 

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


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Jonathan Phillips
(@jonathan_phillips)
Active Member
Joined: 3 months ago
 
Posted by: @joevt

@jonathan_phillips, Did you try the Alogic cable? Otherwise you need USB for those.

 

Hey @joevt -- no, it was the Moshi cable I tried. I'll look up the Alogic cable today ... that or the Belkin. I'm in the UK so getting hold of these cables looks either expensive and/or long delivery times. 

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

.

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