Solved Big Sur Install Trouble (Stuck at RTC: Only Single RAM Bank)

[lordkramgb]

Been trying for a long to time to get into OSX on my 3900x system, but with no luck. Followed the OC guide step and step and get to the following error (attracted screen and EFI folder)
System Specs:
Ryzen 3900x
Asus ROG Crosshair Hero VIII
AMD Rx 580 (Asus Rog 8gb)
1TB Samsung 980 Pro NVME (Updated to latest firmware)
Have bios settings changed as per guide, only issue I have is I cannot disable CSM, as my GPU apparently doesn't support UEFI mode
Have tried enabling and disabling Above 4G Decoding, same result as screenshot
Hoping someone can shed some light on what is wrong, i'm starting to pull my hair out!
(I have previously done a successful install of Big Sur on an Intel Based system)

 

[Edhawk]

Try the EFI folder attached below. It should work with your 12-core CPU and Big Sur.

 

[Aluveitie]

Just a side note, the “RTC: Only Single RAM Bank” is not an indication of your problem. Almost all boards only advertise 128 bytes of RTC memory in the DSDT, even though modern boards have more. MacOS just logs this, but it has no effect. (You can fix that with an SSDT if you want to get rid of that log)

 

[lordkramgb]

Try the EFI folder attached below. It should work with your 12-core CPU and Big Sur.

You are a legend! Finally managed to actually get to the install gui and after many reboots it's finally managed to install and load Big Sur, sound and network are working.
One weird issue I had with my own EFI which I attached is I finally managed to disable CSM in my bios (updated my GPU bios) and I could get into big sur installation, but after about 30 seconds it would automatically crash and reboot, anyway that is irrelevant now, thanks again

 

[Edhawk]

Glad the EFI worked.