Thanks @jstefanop for making this nice device. It works and looks great.
I'm trying to make the Apollo run at it's absolutely quietest setting, even below ECO. It would be awesome if you could answer a few questions I have about it.
ECO: This is the most efficient, quiet, and low power mode. Your Apollo will mine at about 2TH/s in this mode and consume about 120 Watts. The fan should be barely audible in this mode.
Based on the documentation, ECO is set to: -brd_ocp 48 -osc 30.
board power - this controls power/voltage for the board in %. It ranges from 30-95
board frequency - this controls the hashboard's frequency. It ranges from 30-60
Since I would like to run it even lower, I set brd_ocp to 30 and kept osc at 30(both minimums based on the documentation), this nicely decreases the fan speed (and sound) as expected.
My understanding is that the -osc parameter shouldn't affect the fan speed, and only brd_ocp would affect it. Is that correct?
One thing that I don't understand is why the minimum brd_ocp is 30?, would it be safe to run it at even lower numbers?, I'm aware that the hashrate will be reduced of course, but I'm mainly concerned about the hardware functioning properly at it's absolutely lowest value (for example, would it be possible to run it so low that the fans are not needed?).
Also, I noticed there's another fan in the "official" power supply. Since I'm planning to run it with very low power, I wonder if that fan is even needed as that's now the main contributor of noise. I guess I could buy another PSU without a fan for this "silent miner" project. Any suggestions for one? So far I've found
this one, which should run without starting the fan until 220W so it should be absolutely noiseless.
Yes brd_ocp parameter is essentially power draw of the board in %. The board regulates via current instead of voltage (these chips are prone to runaway current if voltage/heat is too high), so this precisely controls how much heat is given off. The downside is that hashrate can vary based on this setting even between units in same environment, and hotter environments will reduce hashrate even if the setting is the same etc.
The UI is limited to 30% to be dumb proof but you could go lower but you'll quickly get into stability issues as voltages below 30% are below what the chips can usually handle. You can't "hurt" the chips with really low power/voltage so you can experiment if you want to find a really low power draw...you can probably achieve ~ 60 watts @1.5 TH.