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Hey all, I've googled this and found a few responses, but not one that has a solid answer on this question, so here is my scenario and question.

We are looking at ordering just over 2000 S9s. We want to place them in mineral oil, and we want to remove the fans or at the very least have them not running. I believe the way that the firmware is setup, the unit won't run without fans. I have read that there may be a way to trick the unit into thinking its attached to a fan by rejigging one of the cables that is plugged into and powers the fans, but comments have been made highlighting that the unit will still want to draw the same amount of power, despite not powering the supposed fans.

A really creative answer was to cut the blades of the fan off, but again, still drawing power to spin the fans, so that is not optimal.

What I'm looking at is a way to either:
a) run the S9 without fans and without taking that additional power that the fans draw.
or
b) run the S9 with the fans, but disable them so they don't take the additional power that they draw.

Is this possible and if so how?

Would much appreciate your advice and input on the matter.

The solution for you is worth money.

If you are building a 2000 rig setup offer a bounty for the answer to this problem.

Willing to hire someone to do it and help us set it up if it can be done. Don't have the money, seeking private funding for it. When I have the money, will gladly pay someone to help us out for sure. Just getting the planning done so it can go into the document that will entice the people with fat stacks :)

Spoofing the tach signal is almost trivial. I could conjure that circuit up over a weekend and have 'em mass produced within probably six weeks. The real question, which this is the first time I've heard of it, is if the S9's controller actively monitors power draw on the fans. If that's the case you'd want a dummy load of some kind, which becomes non-trivial since those fans can pull 30-40W at full tilt. If the whole thing is immersion-cooled, a dummy load becomes easier to pull off because passive cooling requirements are relaxed.

The Antminer does not use power draw to monitor the fan, it uses a tach signal from the fan. It is relatively easy to build a circuit that emulates the tach signal - here is one example: https://www.techidiots.net/notes/fake-fan-sensor (https://www.techidiots.net/notes/fake-fan-sensor)

I hope this helps - looks like you have a nice project in the works!

My partner and I are in Sydney, we re building a farm that runs via a 2 phase cooling setup, like you we need to removed the fans on the S9.

I have found a guy who can create custom firmware and load in to the machines.

This means your machines will run with no fans but and can overclock to about 19th for a 13.5th machine.

Where are you located?

19Th sounds like music to me.
Is this only liquid cooled, or... ?

Can you share this firmware to us?

Seems odd you would be willing to waste a ridiculous amount of money oil cooling these machine but are worried about a little extra power draw from the fans.

Once you have these all immersed and realize you have to physically work on units daily you are going to really regret wasting all that capital when they run just the same air cooled.

Hi,

You solve your problem of fans ?

You can run the S9 without fans simply by modifying bmminer.sh, I don't know why you would mass produce some fake 555 timer circuits to do the same.

Also natively a 13.5 machine won't clock much higher than 18.2 and that's ridiculous power draw anyway.

If you run my firmware the 880v and don't tweak the hash-rate it will do exactly what your trying to do. It will run without a fan check.

https://bitcointalk.org/index.php?topic=4513567.0

Hi,

And do you mean bmminer.sh ou bmminer.bin?
Do you know what code we need to change?

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Hi,

With your bmminer bin there is some fee for another mining pool?

No, taserz is not stealing any hashrate with his bmminer bin.

However, you should definitely learn how to compile it yourself so you can customize it however you like.

Why it says there is no temp control display, that cannot be changed?