Don’t buy S19k pros - run 2 S19J pros for a combined 150T/3400 watts

A few months ago I started to test undervolting 2 S19 J pro 104T models. Each model was different, both 126 chip but one was BM1362AC chips and one was BM1362AI chips. All power tests were conducted on a proper wall reader, not the Luxor power reader.

So now the good stuff of how to do it. Please keep in mind it is possible to damage your hardware but with some common sense it shouldnt be an issue.

You need to install LuxOS, I prefer SD cards but you can use their commander tool for direct install

The best bang for buck I found was the 375mhz profile which is 75T. On my miner (BM1362AC chips) it says 395mhz/12.6V and on my mates miner we tested (BM1362AI chips) it is 395mhx/12.8v.

To undervolt it, you need to create a custom profile, set the mhz as 395 and then from the starting default for that frequency, drop it by 0.1v and test it for an hour or so to ensure that the chip health is good. So for example, in my case my starting voltage is 12.6, so drop it to 12.5, test it for an hour to ensure it’s all good, and then make another profile and go to 12.4v. If all is good and all chip health is green, then go again to 12.3v. I did this to 12v which was fine. However, 3 days later I saw 2 chips go yellow health, so I upped the voltage to 12.1v and it was no issues, everything went back to green. On my mates miner, we dropped his to 12.2v using the method above and then at 12.1v all the chips started to go yellow so we kept it at 12.2v and then everything stayed healthy. so testing bit by bit and paying attention while setting it up is important.

The result of this is 75T for 1700 watts using stock fans. Ill attach a video below of me testing my mates miner, using a Ecoflow battery as a power reader

So whats the benefits of this?

1: Its more efficient than a S19K pro 120T miner (22.6 watts/T)
2: its much cheaper than a S19K pro 120T miner, to buy 2 second hand S19 J pro 104T miners for $500 each and get 150T at the same efficiency, compared to buying a K pro for $1400-$1600 (before shipping) from popular retailers
3: When profits are good, you can run the miners on normal mode and get 208T combined compared to a 120T K pro

It is possible to do this on all miners that are supported by LuxOS but I think you would be crazy to try it on a high profile miner like a S21, but most people cant run their J pros so theres not much risk if something goes wrong, and if a board does go down, LuxOS will still run 2 boards.

LuxOS dev fee is 2.8% but using their OS on their pool, your pool fee will be 0%. If you found this helpful and make a Lux pool account feel free to buy me a beer and enter the code shredz when making a new account.

Any questions please ask



Very nice man!!!:muscle:t5::facepunch:t5::raised_hands:t5:

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Thanks mate, also to put in perspective: 2 J pros for a combined 150T for $1000 is $6.66/T and a K pro for $1600 (with shipping included) is $13/T. And with mining prices of $80 you would pull $12 a day, if you have 10c electric you’d pay $8 per day, if mining prices keep above $80 you’d get your money back in 250 days in the scenario above. Happy mining legends


Thanks for the in-depth message. For me, these forums are all about sharing knowledge and assisting others.


Just want to bump this and talk about how good this is. People talk about once In a lifetime opportunities and I think this is one of them. I have my J pro running at 67T for 1.34kw, which is 20 watts/T.

The S21 200T costs $3700 at best
3 S19 J pros cost $1500 second hand to reach 200T
You need Luxos and you don’t need a SD card

Let’s talk about the price per PH per day.

Using an S21 if you have 10c electric, your break even point is $43/PH
If you use 3 J pros your break even point is $48/PH

So there’s not much wiggle room when mining profits are down

But let’s say mining profits
are good at $150/PH

On an S21 you’d pocket $22 a day and the J pros you’d pocket $23.6, if you ran them on normal mode so 300T, so that’s the tipping point.

If prices were $200/PH a S21 would pocket $32 and the J pros would make $38 a day.

The only thing that S21 miners dominate running 3 J pros at is the resale value if selling the miner is part of your strategy.

I hope this makes sense and I hope more home miners look into this, because just like everything in life if you are doing the same things as everyone else you’ll never get ahead, especially in an industry that’s being industrialised by people with very cheap rates. Happy mining everyone


That is awesome what you have figured out. When you get a chance You should try the epic board. You won’t be disappointed. There’s options like perpetual tuning, voltage modifying and other great Bells and whistles. And there’s no dev fee My S19J pro 104T
Can run efficiently A 110 T. And i’m way under the normal watts of what This machine was running with the bitman board Which was 3550. I’m currently running at 2990W. 62.4°C. 28J/TH
This is the website I got the board at just in case you wanna check it out
Still testing it out. My goal is to hit 135T


That’s awesome mate! I was just running my J pro at 125T during my solar hours using Lux (I have water cooling plates also) might pick one of those control boards up and see how she runs!

Just better keep an eye on your power assuming you have stock PSU, I think they are rated for 240v X 20 amps so if you stick to 80% rule you shouldn’t go over 3800 watts if I’m right? Cheers

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That’s awesome, where did you get your water cooling Plates at? I’ve been wanting to look into that

You’re absolutely right.

When I first plugged the new epic board in i Didn’t modify the Tara hash Or anything
It was already consuming less power then bitman board If I recall right I was down to 2889w at 104T. At 61°C. Anyways, good luck, happy mining.

I got it from Zeus btc mate and their 12kw auto controlled radiator, I can hook more miners up to that system, with only one miner hooked up its silent you can only hear the PSU fans

Wow that’s crazy, is that the wall outlet or the firmware saying 2.2kw? I’ll defs buy some if your wall meter is!

That is off there firmware Off their website. I will get Readings off the wall if you like. I know this chip works better just for the simple fact of.
The Bitman Reading off the wall I was pulling 14.1 amps.
With the new Epic board, I’m reading somewhere around 11.5 to 11.6 Amps Just let me know what kind of readings you want. I’ll even put it back to factory 104 t, so you can see at the wall what it’s showing.

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Adam Moyer.

Ok Here’s the readings at the wall with the epic Bored, at 104 T.

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And with the bitmain board I was sitting higher on amps about 14 amp So the epic board significantly dropped the amp and everything overall.

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That’s awesome, so 537.5mhz and 13.2v for your boards by the look of it? I’ll give that a go tonight and see how mine runs. Thanks for sharing!

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You’re welcome
I’m going to raise it back up to a 105T or a 106T soon. And I’ll share the results if you like.

And this is the result of raising it up to 106T.
Your knowledge and thoughts have helped me out a lot. So I just thought i’d share a little back.
Hope you get one of these boards you won’t regret it happy mining.

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The best result I’ve got while keeping all chips 100% healthy is 68T for 20 watts/T, on my miner thats 11.88v for 350 mhz. I cant get any better efficiency because Lux doesnt allow me to undervolt past 11.88v, im trying to also update on their cmd tool with excel but it wont let me. Id love to try and hit that 17.5 watts/T even if it is at 50-60T. Ill probs break my miner but yolo scared money makes no money