@, well it looks like Big Sur upgraded my Boot Rom EFI, which means I still have the same issues when I reverted back to Catalina... Does anyone have a solution to downgrade the Boot Rom EFI?
You can't since Apple removed the possibility to downgrade your EFI Firmware for security reasons.
First it checks if the firmware version you're trying to install is newer than the one you have and they are now encapsulated in a package with specific hash.
Then the SPI flash memory doesn't have write access before the kernel is loaded. You'll need an external SPI flash programmer to write to the SPI flash memory and it's not a cheap hardware nor a tool designed to be used with little knowledge of what you're doing.
Sadly the risk to brick and render your MacBook Pro unusable is real if you persist in this way.
For more information: Source
2014 Mid 15" MacBook Pro + RX 5700 XT @ 16Gb 1600 MHz DDR3 + macOS 11.1 + Windows 10 20H1
I have a mac mini 2018, i7 6 cores, 32GB ram and a 240 SSD and a Razer EGPU with an AMD RX Vega 64, will it work on Big Sur?
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
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My Vega 56 eGPU works great.
I’ve found Mac Mini eGPU support to be much better on Big Sur than on Catalina.