I overclocked an S19J Pro 104TH in an immersion cooling setup until it shut itself off!
Im pretty surprised how fast these things can actually run in the right conditions!
I measured how much power this bitcoin miner pulls at various overclocking settings, too..
By changing the voltage and clock speed on these machines, you have a choice to either
set off the dynamite to mine as much coin at whatever cost - or you can concentrate
the laser to mine slower, but with incredible efficiency!
The setup..
I think I have reached the Mining She Shed’s final form.
After four iterations, I am now running a single unit tank - this is actually a test
tank from EngineeredFluids.com.
It was designed for GPUs, but it fits pretty perfectly, one single S19j Pro.
I had a mystery leak in my two tank system and it turns out you cant use copper heat
exchangers to heat the pool, Chlorine eats copper brazing, who knew..
This time, this, the fourth version of this kit now has Two pumps, pumping into two pretty
hearty radiators, each rated to extract 200,000 btus of heat on two totally separate cooling
loops - that BTU number can be misleading when youre sizing a radiator for immersion
cooling because BitCool doesnt transfer heat as well as water does, actually pretty much
nothing does, and water is how these radiators get their ratings, but each one of these should
be sufficient to cool the miner alone if the other one craps out..
The reason for this overkill is so that when testing overclocks, heat buildup will not
be the bottleneck..
Itll be power, or whatever clock speed that the chips can handle.
The two lines from the radiators pump into the bottom of this tank, one line on each
side, then bit cool is forced in through just the fan openings to the hashboards thanks
to this little flow plate that fits into the bottom of this tank, up through the S19j Pro,
then it spills over this ledge on the inside of the tank and down into a separate hot chamber,
where the heated bitcool is sucked back into the pumps, directed into the radiators so
they can ring the heat out and give me another excuse to use these fire effects I do so enjoy.
I see four reasons to immersion cool your miners.
First, longevity - by cooling these in a bath of dielectric coolant, youre removing two
of the main things that tend to cause failure in these machines - Vibration, from fans - and
heat fluctuation.
Day and night cycles cause the ambient heat of the air youre pulling through your machines
to change every night and every afternoon, in an air-cooled situation.
Since we have multiple types of metal components; mainly copper, aluminum, steel and whatever
solder is made out of - the points where they come into contact with each other will expand
and contract at a different pace, microscopically.
Over a long period of time, and mixed with a ton of vibration from the fans on these
machines, tiny little cracks can start to form.
This is what leads to a heat sync falling off, and can be the cause of a single chip
on a board to stop responding because of a microscopic gap in the connection.
Of course, we’ve seen L3’s last for going on 5 years now, so this definitely isnt a
MAJOR problem, but the ‘normalization’ of temperature that immersion cooling provides
will prevent this phenomenon.
Reason two to go with immersion cooling is maintenance.
As long as you buy high quality pumps and parts, everything should just hum along for
a very long time without anything going wrong - you dont have to open machines and blow
dust out, you dont have to change filters or replace burnt out fans.. you just have
to check once in a while to make sure everything is still running.
Then we have the noise.
These big fans on the radiators are far from silent - but they live outside, so you could
have a setup like this in your garage and with the door shut, the other people in your
house would never threaten to leave you over your 11 dollars a day.
Finally, OVERCLOCK.
If you want to overclock your bitcoin miners and you dont live in the north pole year round,
it will behoove you to cool them in a tank of dielectric coolant.
You can get away with a light overclock, something like 5-10% on air-cooling, but you’ll be
pushing up the temperatures of your miners if you do.
Today - I set out to overclock this S19J Pro 104TH machine to its limit.
Also, Ive taken the time to crank it up incrementally and take amp measurements to see just how
many watts this machine will pull at different settings.
Im using the ASIC.TO overclocking firmware - Braiins still doesnt make one for the type
of control board in all of my machines.
You can find this firmware on asic.to's telegram page.
Ill link that in the description here - they have a pinned message at the top of the conversation
where you can download the newest version of the firmware.
The most current firmware 1.1.7 is a disk image, so download the version that goes with
your board, bb for beagle bone.
Here is what a Beagle Bone Board looks like - here is what a Xilinx board looks like - notice
the placement of the sd card slot compared to the ethernet port.
If your machine has no SD card slot, youre so far out of luck.
Then, go on out and get yourself this piece of software called Balena Etcher.
This works on Mac or Windows.
Open it, choose flash from file, point to that file you just downloaded, select target
- you’ll need a microUSB card that is 8GB or smaller - select it, and hit flash!
Thats its, now you can just plop that card in the card slot and restart the machine.
I didnt want to take my machine out of the bath, so I had a fun little dexterity challenge
with this tiny little card, going into this tiny little card slot which was facing down
and up against the wall of this tank..
But I made it happen, even if I did use my left hand and dunk my apple watch in the process.
Whoopsidaisy!
Sp you’ll notice everything looks a lot different inside this firmware.
How lovely.
Here was this machine stock - it ran for 43 days uninterrupted, so stable!
Its a 104TH machine, looks like it was running just a tiny bit over that with the hottest
temperatures in the 60’s.
The reason it says the hot side is the inlet is because I dunked this machine “the easy
way” so coolant is going in the out - it is slightly more efficient to put it in the
other way.
But its super hard to plug stuff in if you dont have a ‘flip kit’ sold by EngineeredFluids.com.
I dont.
While its starting up, you can press the log button on the bottom left if you want to see
what its doing..
Itll take about 5 minutes of running to find its footing and run at whatever speed its
going to..
You can see what each board is doing down here, the voltage starts high and adjusts
itself down to where you set it, looking for stability.
For a baseline - here is a stock S19J Pro 104 running stock firmware on air cooled,
the way bitmain intended..
My power measures just over 240 volts (242v) and this machine drinks up 12.2 amps.
Multiply those numbers together to get 2952 watts.
Theres a little preset dropdown menu in the mining overclock settings - if you choose
the 2970w 100Th preset..
Let it run its course - you’ll get a little over 100 terahash but at 11 AMPS!
At 240v thats only 2640 watts!!
The amp meter doesnt lie - this is super efficient!
Im sure the fact that its running four less fans than a stock air cooled unit plays no
small part.
But maybe you dont care about efficiency - you dont want an electric car - you want a fucking
Koenigisegg one:1…
You want to push that little button on the shifter and run your S19 on software NOS..
You want to drink red bull and headbang at a hurricane!!!
Well, hold on, DOM…
You really should take this one step at a time in order to figure out where you can
take your miner - you may have heard the term ‘silicon lottery,’ describing how all
these chips randomly have different performance metrics, even with the same settings - so
your own machine does have some… perfect setting… if you took enough time to look
for it.
Back over in Mining, then overclocking - then scroll down..
These three squares represent the three hashboards in your S19J pro..
And ALL these little boxes are the individual chips..
You can see how theyre all hashing at different speeds..
You CAN even go as far as to get in here and find the best performing ones, and individually
crank them up to totally maximize the board..
Unfortunately you have to do a restart every time you change anything in order to see the
changes take effect - and thats why autotune, like on the braiins software, takes hours
and hours, it will automatically and systematically go through all the chips and try different
settings to find the best performance.
Im not doing that here - Im using the global sliders to crank the voltage and clock speed
on the whole machine at once instead.
So for the overclock a conservative 14.1v, up from the default 13.4 - and then 625 Mhz
on the chips..
Hit save, hit apply, let ‘er rip..
That gets us up to 116-117 terahash and now were pulling 14.6 amps at 240 volts..
Thats 3504 watts.
Thats a 12 and a half percent hash bump for 16% more power.
Not terrible!
Lets turn up the voltage from 14.1 to 14.6 - and the clock speed from 625 to 645…
After the machine boots back up and ramps back up now were pushing 122TH and the amp
meter says were pulling 17 amps - 4080 watts!!
So for an extra 17% of hash rate, were using 33% more power than a stock S19j pro.
Its starting to let go of efficiency here, but in the name of “satoshis at any cost…
“
We’ve still got some room on these sliders…
At 14.9 volts with the clock set to 750 Mhz I was able to get this 104 terahash S19j Pro
to run stable at just a hair over 130TH, sometimes jumping up in the upper 130’s, with zero
hardware errors and no rejected shares..
This at a cost of pulling a whopping 20.2 amps from the wall for a single machine - thats
4888 watts, 65% more electricity than stock - achieving a hash rate 25% higher than stock
- efficiency is clear out the window - were pulling a trailer up hill and against the
wind on the terahash highway with a super car stuck in fourth gear - sure its faster,
but its getting 4 miles to the gallon, you sociopath.
But you look over and say never mind while putting your foot the rest of the way to the
floor (15volts!) just to hear the engine roar a little louder and…… chain break detected.
Chain break detected.
We’ve gone too far.
We peaked into the vortex because we just wanted to see it, but then everything went
black.
Well, really the power supply simply cant provide more than 15 volts, and you’d need
more than 15 volts for these 378 chips to hit 800 Mhz.. its just that simple.
130 terahash. 130 Terahash is the stable limit for THIS S19J Pro without an alteration to
its power supply.
I wonder, then, what is the limit of yours.