White screen with EGPU only connected

No changes for me. Upon upgrade to 10.15.1, my eGPU did not work. Removing the case and disconnecting/reconnecting power worked to bring it back to previous state. I seem to need to have a display connected to HDMI during startup. After logging in, I switch my displays to the eGPU and disconnect the HDMI. Upon putting computer to sleep and then waking it, both external displays are working off of eGPU. Very inconvenient procedure. Not plug-and-play. But it works.

No changes for me either after installing 10.15.1. (White screen of death). During the install, temperatures soared on the Mac mini as well as the EGPU. I had to power down during the install to prevent damaging the hardware. When restoring the power, I power on the Mac Mini, and 5 seconds later, power on the EGPU, and this allows the Mac Mini enough time to get past the initial boot sequence, and then it detects the presence of the EGPU and finishes the startup using the EGPU.

I now perform the delayed power to the EGPU at startup, every time and the mini detects the EGPU every time. I have no other monitor connected. Not the greatest work-around but not the end of the world either.

As a side note, I no longer have a problem with my back-up drive (with Mojave) that would not wake up after the system would go to sleep. Time machine would always complain that the drive was no longer available. A system re-start was required to recognize the external drive. With Catalina, I no longer have that problem.

One thing fixed, and one thing broken! Maybe the EGPU fix will be in the next update!

I have Sonnet 550 with RX480. With my monitor plugged into the Sonnet and the Sonnet plugged into the Mac Mini 2018, the system will not even boot. The Apple logo comes up then the screen turns black and that is it...DOA.

Both of these products were listed on Apple's approved use list on their website . Now I have a $700 investment (not counting the Mac Mini) that is worthless. Catalina broke this real good. I am sure that they can fix it with an update...question is...do they care enough to do so?

I don't believe there is an elegant retreat to Mojave. If there is, someone should share it here.

I have a Sonnet and RX580 as well. I have found that if I start with both the Mac Mini and the Sonnet powered off, and turn the Mac Mini on, and 5 seconds later turn the power on on the Sonnet, the system boots normally and the Sonnet is recognized and works as before. I do not have any other monitor plugged into the HDMI port, only the Sonnet connected to the Mac Mini Thunderbolt 3 port. Please give this a try and let me know if it works for you.

My understanding is that fallback to Mojave is not possible as the firmware in the mini was overwritten by the Catalyst release, so there's no going back.

Good luck!

I started having the same issue in Mojave after the latest security update.... I reinstalled the OS (version before the update) and everything I back to normal. 2018 Mac mini i7, Akitio Node EGPU, RX580 with three Dell U3014s...

Sonnet just sent me this... No help at all. We already knew this. Sonnet seems to be as clueless about this as we are.

“Hello, 

Here is our latest information about using the Mac mini with Catalina and an eGPU.

Under macOS 10.15 and 10.15.1, a 2018 Mac mini with a Vega 56, Vega 64, WX 8200, WX 9100, Radeon 5700, or Radeon 5700 XT can boot with a monitor connected only to the GPU card; a 2018 Mac mini with an RX 560/570/580/590 must be booted with a monitor connected to the Mac mini’s HDMI port. The monitor may be moved to the GPU after booting.

Let us know if this helps.”

I too have had this problem since the security update to Mojave, as I won’t be ready to switch to Catalina for a while, but for me, I have to boot with the HDMI cable connected directly to the mini, then hot-swap it to the Sonnet Breakaway Box 500w with AMD RX 580. The Apple logo appears, which never used to happen, then the display blinks to black and nothing happens, and I have to turn off the computer by holding down the power button. The fan goes into hyperdrive only occasionally when the HDMI cable is attached to the EGPU when booting.

With help from the Apple tech, we booted into safe mode, which was supposed to fix the problem, but nothing happened. Additionally, the option to prefer EGPU still isn’t available within the Displays options. The tech help at Apple insisted that it was a hardware issue with the box and GPU. If nothing was wrong before the security update, how is this a hardware issue? Any help is appreciated! Peace.

It seems the latest Mojave update contained this horrid Mac Mini 2018 firmware update that breaks polaris eGPUs.

What is your boot rom version? You can check it here:

Apple logo -> About this Mac -> System report -> Hardware -> Boot ROM Version:

The "Prefer eGPU" option is not under "Displays", but you have to select an individual apps and choose "Get Info" in the contect menu and there select "Prefer External GPU".

The symptoms you describe are the same as for others. This is not really a Catalina specific issue, but a problem with the latest Mac Mini 2018 firmware which contains boot screen support for eGPUs (that's why you see the Apple logo during boot). It seems with the boot screen enabled when the OS level Polaris (RX550-RX590) graphics drivers kick in it can't reinitalize the card properly (?), a blank white screen (for DP, usually a black screen for HDMI) appears and the GPU fan goes to 100%.

This problematic firmware update was first deployed during Catalina installation, but if a Catalina user downgraded to Mojave it did not fix the eGPU boot problem, since it is firmware related. Now it seems even Mojave users receive this firmware in form of a security update. So no escape! :)

It isn't a fault with the hardware as sole the mini works fine. I'd be interested to know if the official Apple eGPU box using RX5 series is having the same issue. Plus I'm not being funny but taking a whole eGPU setup to an Apple store knowing this is a driver issue as part of a firmware upgrade I have zero faith they can do anything about it! It will require a fix from Apple software team at firmware level. Hopefully this thread will sort get noticed (especially now it is happening with Mojave latest update as well!)

One good bit of news is having just googled the issue there are a fair few tech sites highlighting it now (and confirm even happening with Apple developer recommended kits) so hopefully a fix will happen in next few months (I am using a NUC linked to eGPU) instead. Frustrating thing is my eGPU also has a 1TB SSD in where I store all my data vs the 256GB internal model with 32GB upgrade. Makes me not bother using what I paid a fair bit for vs my older iMac 2012 as we all use Mac so we don't have none stop driver issues and upgrades (I'd have been better using the eGPU hacks with an Nvidia card vs buying RX580 atm!) Also not everyone has the ability to just swap machines!

I'm still using OSX Mojave on my 2018 mac mini with RX580 egpu, but yesterday without warning i cannot boot into my mac with connected egpu.

PLEASE APPLE HAS THIS FIXED! Thunderbolt 3 for what if you don't allow device to connect!

Catalina broke most if not all of the previously supported eGPU boxes. Reverting to Mojave is not an option for most of us but it is most interesting to hear that Apple has now broke that as well. I have taken my video card (RX 480) out of my Sonnet 550 and returned to it my Windows machine. What a pity...bad on Apple.

Yes...I spent an hour on the phone with several of their 'experts'. They were clueless at that time and claimed that no one had put in a ticket request. I am hoping that most of the people that use the forums have done so by now as this was right after the Catalina debut. The only way this will ever get fixed is to complain directly to Apple. I doubt they pay much, if any attention to the forums.