Does the stock fan continue running at 1800RPM even when it's set to 1% for any temperature (-fan_pwm_low 1 -fan_pwm_hi 1)?
Some of them do, and all of mine do.
jstefanop mentioned that Futurebit had supply problems during Covid and had to source a number of different fans, so different Apollo's might have a different fan.
It is not necessary to use the Standard Apollo and command line interface in a terminal with
-fan_pwm_hi 1
to verify which type of fan is in a specific Apollo. But it is very educational and I'm glad I started to stumnble down that path.
To easily test the capabilities if the miner fan in a Full Package Apollo the owner can simply set the Miner fan speed in the GUI of the Full Package Apollo to something like 60c/65c and then restart the miner. The fan should then run at it's lowest possible speed, that could be 0 rpm or higher, until the miner temp reaches 60c.