Can somebody please tell me if I get this right:
The difference between the fixed frequenc firmwares is the voltage, right? So If I load the 650M firmware on a S9 with stock 14TH, it will assume it has good chips and give them LOWER voltage than the 600M firmware, right?

So could i just load the 650M firmware on my S9 and check what frequency it accepts?
Problem is that as soon as I load the fixed frequency firmware, the temps show above 100°C. But i think the readings are not right...

Any advice?