okay the boards work with

all S19
and t21
and s21


When you under clock it allows you to disable any of the 3 boards

it also allows as low as 50mhz freq and 12 volts if you do manual.

you can also go way high like 600 freq and 15 volts
and that are the manual settings

more than that you can autotune from 60th to 300th   on the t21 I have.

the flexibility is huge much more like a gpu from the old days of mining.

You also may find you a board that allows really low settings and another board that allows high settings.


t21 thread

https://bitcointalk.org/index.php?topic=5491800.0