This is what I run in my MacPro have a look here too
#4,648
For the memory config I followed the Apple MacPro 2019 scheme ->
https://support.apple.com/en-us/HT210103
8 DIMMs is the one we need, note still shows 12 slots. I have configured it on 12 slots scheme because I did not want to see the notification, which as no incidence whatsoever. You would put 1.5TB memory config that it would not change anything.
However when I tried the set the 8 slots according to the supported configuration I would get the error notification. So I reverted back to 12 slots configuration even though we only have 8 slots and the error's gone.
I guess that in the near future if IOIIIO works on the kext notification disabler, that we can properly set the memory config to reflect the true memory configuration of our MacPro5,1.
I preferred to set it that way so 1 less .kext in the driver folder.
I would love to have it configured this way which reflect the true config but then you get error and orange check, which I don't like