We have been picking up reports that some External Graphics Processor Units (eGPU) have issues with macOS Catalina 10.15. We have the details…

Until the release of macOS Catalina it looked as if Apple was continuing to improve how their Macs work with eGPUs, but with macOS 10.15 we have been seeing reports of some users are finding that their Macs may now no longer drive their eGPUs as expected.

In our article How To Block macOS Mojave From Upgrading To macOS Catalina community member ‘alanmcd’ commented…

“I have Mac Mini 2018 with eGPU RX580 ("supported developer H/W") which reeks havoc under Catalina. The daily and sometimes more choice between "Restart to Install, or "Remind Me Later" have been very annoying.”

From our research, ‘alanmcd’ is not alone. it appears to be related to specific combinations of Macs and eGPUs with the Radeon 570 and 580-based eGPUs most affected when used with a Mac mini, which are two of the Apple Approved eGPUs.

Users have reported that the issues include not being able to boot up the Mac with a display connected to the eGPU. For some, if the Mac will start, with the monitor attached to the eGPU, the Mac mini immediately restarts, whilst others report their Macs freezing.

Sonnet, in their macOS Catalina compatibility chart, are advising users of their eGPUs not to upgrade to macOS Catalina…

“Do not update a 2018 Mac Mini to Catalina if you intend to use an eGPU. 2018 Mac mini users have reported a number of issues with Catalina with an eGPU.”

Still No Nvidia Support

Of course the elephant in the room is that Apple still don’t support anything made by Nvidia.

Good News - Vega Cards Seem OK

However, it is not all bad news, we understand that Vega 56, Vega 64, and Vega VII cards installed in any eGPU enclosure that can provide enough power are not affected by these issues. In addition apparently if you have an eGPU installed and connected to a Mac, but with the display connected directly to the Mac and not through the GPU, it will still do its stuff like video processing without any problems.

More On macOS Catalina Compatibility

If you want to know more about macOS Catalina support and compatibility then do check our article macOS Catalina Compatibility - The Ultimate Pro Audio Guide with its searchable database to see it the software and hardware you use is compatible with macOS Catalina yet.