Very interesting.
I have 72 cards. Rx580 8g Nitro + only. They run on Windows and i Was waiting for proper oc and voltage management  in SMOS prior to switching.

All my cards have modded bios. Not the voltage but bios timing straps only.
Anyone has experience with modded straps ?
Today On Windows i get 31,5mhs eth + 980 mhs dcr @1000w for 6 cards. VCore @1150/900  Vram@ 2200/900

 I should start migration by tomorrow, hope i will get similar résults