White screen with EGPU only connected

This is a known and repeatedly reported issue which was sadly overlooked during the Catalina Betas by the Apple team. The issue is dubbed "white screen of death"

The problem mostly affects the 2018 Mac Mini running Catalina connected to a AMD Radeon RX570 or RX580 based eGPU.

The symptom is mostly a blank white screen (sometimes black or magenta) upon boot and excessive GPU heat which causes the GPU fans to spin to full speed after a while.

You have to do the following to live with the issue:

• When the white screen appears, turn off your eGPU for 5 seconds and then turn back on. The login screen should appear normally.
• Turn off "Start up automatically after a power failure" under Settings/Energy Saver
• Turn off "Install macOS updates" under Settings/Software Update/Advanced...

The last two actions are needed to prevent your Mac to boot to a white screen unattended causing your eGPU to overheat for extended periods of time (this might cause further hardware related problems).

See these discussions for more information:

https://egpu.io/forums/mac-setup/state-of-egpu-for-macs-catalina-10-15-update

https://egpu.io/forums/mac-setup/macos-catalina-tidbits-egpu-updates/paged/2/

https://forums.macrumors.com/threads/catalina-egpu.2193797/page-4?post=27853347#post-27853347

https://forums.macrumors.com/threads/mac-mini-2018-hot-egpu-fan-full-throttle-after-upgrading.2204860/

https://www.reddit.com/r/eGPU/comments/dex36o/egfx_breakaway_box_550_amd_580_catalina_troubles/

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!

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!

After the update 10.15.2 I have noticed that I cannot boot into Mac OS when I only use eGPU + monitor. The workaround is to type password blindly, then in couple of seconds Mac mini Boots into OS via eGPU. This must be software related as it worked before the update. If you use Bluetooth keyboard, couple of first keystrokes may not be registered. I hit random letter and backspace 2 times and then start to type my log in password.

Daniel

I Installed 10.15.4. I can now boot up in my Egpu without doing anything. No white screen or black. The fans rev up for a second and then spin down to normal and then login screen shows up. So in my case it looks like 10.15.4 nights of temp fix it? Let me know

10.15.4 works fine for me. Config: 2018 Mac Mini, RX570 in Breakaway Box, two monitors. FileVault enabled.

Left monitor is connected to two port HDMI switch: one port Mac Mini HDMI port, the other to RX570 HDMI.

Right Monitor connected to DisplayPort on RX570.

Before restart or boot, I switch the left monitor HDMI switch to the Mini.  Once booted I switch it back to R570.  

I have had no problems with this configuration.  While it is booting I may see some strange stuff on the right monitor, but that clears up by the end of the boot process.  The right monitor is my primary monitor (in Display Preferences).

Presumably you could do this just using different inputs on the monitor, but the HDMI switch was more convenient in my setup.

Finally the newly released 10.15.4 beta 2 seems to fix the problem for me. :)

Mac Mini 2018 + RX 570 eGPU

Boot ROM version: 1037.100.340.0.0 (iBridge: 17.16.14236.5.2,0)

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.

Same issue with RX560 in Breakaway Box running Mojave on 2018 Mini. Problem started after latest security update.

I have a second monitor connected to the HDMI port - that does not avoid the problem if eGPU is powered. The workaround I use is:

1. Boot with eGPU powered off with second monitor on HDMI
2. After login complete, I turn on eGPU then move second monitor to eGPU. Both monitors behave normally

I am running FileVault so I have my second monitor on an HDMI switch that allows me to trivially move the second monitor between Mac HDMI and RX560.

The best workaround I've found is to boot, wait for white/black screen, then unplug and replug your EGPU. Triggers login in screen for me. It's an extra step for sure but works consistently for me on boot.

Don't forget to make a ticket with Sonnet and Apple. Maybe with enough people they'll actually try to fix this issue.

Btw, if you keep your monitor off during boot and turn it on when the login screen is up you won't have any issues. Otherwise, you'll have to power off for five seconds to get it going.

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! :)

On Mac mini 2018+RX 580 eGPU.

Like others reported, 10.15.2 update left me a black screen when the mac restarted for the update. Switching to non-eGPU output did not help, but a force shutdown and boot without eGPU connection helped me into the system. Notice there is a roughly 8-min update process during the first boot, and that might be the reason eGPU gave you black screen.

After the update is fully completed, I shutdown the mac again, plugged in the video cable from eGPU, and boot the mac again like in 15.10.1 (my way is to turn on mac without eGPU on, input password blindly, and wait a while until the the boot process is complete, then turn on the power for eGPU; this bypasses seeing a white screen and forcefully shutdown once during the process). It works.