Blackmagic Forum

Can't get the Mac Mini to work with the eGPU and Samsung Thunderbolt monitor. The eGPU and the Macbook Pro i have work perfectly together when I connect the Macbook Pro to the eGPU and then the eGPU to the monitor using Thunderbolt 3 cables. However when I duplicate that on the new Mac Mini the signal never gets to the monitor. I tested this with the same cables and obviously the same monitors. If i connect the mac mini to the eGPU and directly to the monitor I can see that the software integration works and the eGPU is recognized in the menu bar as well as in the system monitor. Obviously that's not the optimum configuration so looking for help before I return the unit. Talked to Apple support and they didn't have any ideas. Hope someone here has the answers.

Hi, I'm having the same problem with the Mac Mini, BM eGPU (Radeon 580) and LG 4K monitor with USB-C input. The monitor is an LG 27ud88-w 4K display. I'm using a Thunderbolt 3 cable to connect the mini to the eGPU and USB-C cable from eGPU to monitor. HDMI cable works a bit better, but only at 30hz and no booting.

Mac Mini > LG 4K = fine

Mac Mini > LG 4K + Mac Mini > eGPU = fine

Mac Mini > eGPU > LG 4K = no signal at all, black screen with empty menu bar and mouse pointer or 'normal' image but with lower resolution (1080p).

The last option should be the best way, when reading reviews from Macbook users. But on the Mac Mini it's not working or unreliable. Why? A closed Macbook isn't much different from a Mac Mini right?

What should be the way to go?

OK, got it working now.
I think HDMI was running at 30hz was a monitor issue rather than the eGPU.

The way I have it setup right now is with a HDMI (2.0) cable from the eGPU to the monitor. No boot screen, but that's because the eGPU gets loaded/connected after the OS is booted I think.

The thing you have to disable is FileVault to get it properly boot when the monitor is connected straight to the eGPU.

USB-C/Thunderbolt connection with the monitor still doesn't work.

Same problem here:

Mac Mini (2018) > eGPU > LG 34UC99-W via USB-C doesn't work properly.
However, I made it work SOMETIMES by unplugging and plugging the USB-C cable. But every restart is leading to the same problem: Black Screen
Such a shame...
Will this setup ever work? Are there updates in this regard in (probably near) future?

With best wishes for a Merry Christmas and a Happy New Year from Germany.

I did some reading up on it as I am interested in this combo.

I’ve read a few things that might help.

Plug the monitor into the Mac mini via its graphic card for loading (hdmi port) and then the eGPU into a display port if your monitor can take both. That way you can show the boot screen and switch the signal over to the eGPU when loaded.

Use the usb-c / tb3 port closest to the hdmi port for the eGPU.

And I’d go and visit the egpu dot io webpage for resources and forum posts on this combo.

Exactly the same problem connecting my LG 34WK95U.

Mac Mini 2018 -> eGPU (Thunderbolt 3) -> LG 34WK95U (also Thunderbolt 3), monitor wakes up, stays black, after few second "no signal" and then turning on power saving mode.

Unplugging and replugging the thunderbolt in the eGPU most of the times restores my connection. After every reboot I need to perform the again. Coming out of sleep mode works OK.

When I connect my Mac mini directly to my monitor it works OK.

So conclusion is that it must have something to do with how the eGPU initializes the monitor, or the way macOS loads drivers.

I do hope that BlackMagicDesign and Apple are giving top priority in fixing this. Many reports on the internet about similar problems. One of them said that Apple was aware of the problem and working own a fix.

A true shame this setup is not working.

Best wishes from The Netherlands.

neosolyt wrote:Same problem here:

Mac Mini (2018) > eGPU > LG 34UC99-W via USB-C doesn't work properly.
However, I made it work SOMETIMES by unplugging and plugging the USB-C cable. But every restart is leading to the same problem: Black Screen
Such a shame...
Will this setup ever work? Are there updates in this regard in (probably near) future?

With best wishes for a Merry Christmas and a Happy New Year from Germany.

For me I also think I experience the same issue.
Mac Mini -> Black Magic eGPU -HDMI-> BenQ GW2406Z.

First boot always seems to go black. When shutting down the mac mini by holding the powerbutton and powering again. The setup boots normal without a black screen.

I was thinking this is an issue with my Bluetooth Mouse as I had issues regarding not booting due to to T2 chip. But as it seems more people are having a black screen on boot.

Will try the suggested plugging and unplugging of the different cables .

I had the same issue with the LG displays. The fix is so wildly simple, that I overlooked it for weeks. The only way to update the firmware on LG thunderbolt displays is with an app they released in the macOS App Store. Install the app, update the firmware, reboot, update again if needed, and uninstall the app as it is mostly useless. That will fix the problem.


LG Screen Manager (LG Monitor) by LG Electronics, Inc. https://itunes.apple.com/us/app/lg-scre ... 1783?mt=12

We were doing a set up with the Mac mini 2018, Blackmagic eGPU and an LG Ultrafine 5K. Checked the firmware updates through the LG Screen Manager App and we were up to date. Had to switch to new Thunderbolt Cable the LG cables provided with the display must not have been 40Gbs 100W - once we switched out cables its been running fine. Initial setup was problematic in that we were getting what seemed like random flashing black screens every few minutes. Random or connected to a certain tasks - we could not be certain. After a restart the flashing has stopped. We will now proceed to doing some video editing with final cut and premiere and see how things go.

Anyone having problems since the Big Sur update? I have a 2018 Mac mini and the BM eGPU. Getting a lot of system crashes and notice AMD in the crash log


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