The lack of external GPU support in Apple Silicon M1 Macs may only be temporary, as a connected eGPU is still detected but does nothing.
The introduction of the M1-equipped Macs, including Mac mini, MacBook Air and 13-inch MacBook Pro, alienated the GPU on the processor, but signs that support for eGPUs was on the way out. Evidence for developer support and later experiments confirmed that support for non-Apple GPUs would not be enabled in hardware using Apple Silicon, effectively rendering eGPUs largely unusable.
However, test of Mac4Ever confirmed by AppleInsider‘s own trials, offer hope to eGPU owners. While eGPUs are not officially supported by the latest M1
By connecting a Pro Display XDR to a Blackmagic eGPU inserted into a Thunderbolt 3 port, it was found that the eGPU case was still found and working. The screen communicates with the MacBook Pro as usual, complete with video playback.
other than that AppleInsider have seen the same behavior in the Razer Core X and Sonnet eGFX Breakaway Box with a selection of cards including the RX 590, Vega 64 and Radeon VII.
The Radeon 580 GPU included in the above case is not actively used for graphics acceleration, nor any of the cards we have tested. Lack of drivers is the most obvious reason for the lack of support, but weird relationships with how Apple has implemented Thunderbolt or external PCI-E addressing can also be contributing factors.
This discovery leads to the possibility that Apple will reintroduce eGPU support in the future. It will have to arrive as an update to macOS Big Sur, a new M-series chipstart or possibly both.
Apple’s support for eGPUs came with a spring update for macOS Mojave – with a complete lack of support for Nvidia cards. The core technology works properly in macOS Big Sur with a selection of Intel Mac computers.