What an Antminer S19K Pro actually mined, from its first winter to today

Bought once its price settled after launch, racked in Argentina at 6¢, run through a halving, and moved to Nigeria once cheap power had spent a year paying decisively better. Not one sat sold — and it has already covered its own hardware.

An Antminer S19K Pro photographed against a container port

Bitmain Antminer S19K Pro (120 TH/s)

August 2023: the machine everyone could afford

Bitcoin was around $26,000. The halving was a date on a calendar that nobody was pricing in yet. Bitmain had just put the Antminer S19K Pro on the market at about $1,820 for the 120 TH version, and after two years of $3,000 machines it felt like the door had been opened. Fifteen dollars a terahash. You could start mining for the price of a used car engine.

We did not buy at that price. We waited for it to settle and bought in November 2023 at $1,701. Landed at our Argentina site — machine, freight, import duty, customs, rack space and setup — the all-in was $2,676. Argentina charges import duty and a broker fee, and together they add almost as much again as the freight. That is the number that matters, and it is the number most buyers never write down. Everything that follows is measured against it.

The site is the half of the story nobody markets. Six cents a kilowatt-hour, and over the past twenty-four months it has run above 99% uptime. Uptime is the variable nobody markets and everybody pays for: a machine that is off is a machine paying rent on capital while producing nothing.

The months before the halving were the whole party

From the day we bought it to the halving in April 2024 the machine ran 156 days and put 0.0350 BTC in the wallet, clearing about $7.07 a day after electricity. At that rate the arithmetic looked wonderful — a little over a year to pay for itself, and then free money.

That arithmetic was a lie, and the reason it was a lie was printed in the protocol years in advance. On 20 April 2024 the block subsidy halved, and every machine on earth started producing half as many coins for the same electricity.

The 929 days since have produced 0.0573 BTC — more coins, but over a far longer stretch — at about $1.63 a day after power. Same machine. The first 14% of its working life delivered 38% of everything it has ever made. If you take one thing from this piece, take that sentence and apply it to whatever you are being sold today.

It produced 38% of every coin it has ever made in the first 14% of its life.

Chart: Profit over electricity, month by month: 6¢ in Argentina, then 3.9¢ in Nigeria after the move (dashed line). The dip in April 2024 is the halving.

Grinding through the middle

What follows a halving is not a crash, it is a grind. Difficulty kept climbing because better machines kept arriving. Our machine kept doing exactly what it was built to do, at a slowly shrinking share of a slowly growing network. There was no drama. There was just a daily number that got smaller.

What mattered was the one number that never stopped moving in the right direction: coins kept. Every day the machine turned electricity into bitcoin, and every one of those coins stayed in the stack.

That is the real subject of this article. A miner is a converter that turns cheap electricity into bitcoin, and this one did exactly what it was bought to do, every single day, through a halving and out the other side.

Chart: What a coin cost in electricity each month, against what a coin was worth. The gap is the margin.

The tally so far

Across 1,085 days it mined and kept 0.0923 BTC. Not one sat was sold — the power bill was paid out of pocket, which is the only way to run this if you actually want the bitcoin. Electricity came to about $3,856. The hardware was $2,676 landed. Those coins are worth about $7,077 today.

The hardware does not get subtracted from that, because we are not selling it — it is still mining. Put it plainly: $3,856 of electricity bought 0.0923 BTC, about $41,800 a coin, and those coins are worth roughly $7,077 today. Cashflow of $3,222 against a box that cost $2,676 landed — it has covered its own hardware 1.2× over, and is still going.

That $41,800 is a lifetime average, against a bitcoin that trades at $80,372 today — every sat was made for a fraction of what it is worth. It is not what the machine does today: at today’s difficulty a coin costs it more, which is why it moved to cheaper power, where it has a long second act ahead of it.

Chart: Coins accumulated over the machine’s life, and what they are worth held versus sold on the day they were mined.

Moved to Nigeria, 20 January 2026

It spent 796 days in Argentina — more than two years, most of a working life. On 20 January 2026 it went to Nigeria, and it has been there ever since: 289 days, and it will not be moved again.

The trigger was not the machine failing to clear at 6¢ — it was a full year in which Nigeria paid decisively better. Nigeria runs a lower uptime than Argentina, so it mines fewer coins per year, but at 3.9¢ it mines them for a third less. Once hashprice fell far enough that the power bill mattered more than the extra uptime, Nigeria won, and the machine went on a truck that month rather than a year later.

This is the part of the lifecycle people miss. Machines do not stop being useful when they stop clearing at your rate; they migrate to cheaper power and keep producing. Our older fleet does its longest stretch in Nigeria for exactly this reason, and that stretch routinely runs years longer than anyone expects.

An old machine is not finished. It is finished at that price of electricity.

Stacked shipping containers and a gantry crane at a port — Argentina to Nigeria is a freight job. A machine that has run out of headroom at one rate keeps producing at a cheaper one.

The second one: $271 for the box, $1,291 on the floor

In April 2026 a new 120 TH S19K Pro could be had for $271. Not a typo and not a broken unit — the same machine, new, at the point where a 23 J/TH box had become a commodity.

We bought one and sent it straight to Nigeria rather than Argentina, because at 3.9¢ a machine this inefficient has a future and at 6¢ it does not. The box was $271. Freight added $350, rack infrastructure $250, setup $200, the backup PSU Nigeria requires another $125, and import duty and customs brokerage $95 on top — $1,291 landed. The machine was 21% of the bill. Each coin it makes costs more in electricity than the original unit’s did in its early years, and it does not matter, because the box cost a fraction as much.

At that entry the power rate is the only variable left, and at 3.9¢ it has years of cashflow ahead of it. That is the lesson of this model in one purchase: at the right entry and the right site, a machine everybody had stopped talking about was the best hashrate-per-dollar on the board.

The machine was 21% of the bill. Getting it to the rack was the other 79%.

What we would tell the version of us standing there in August 2023

Buy the more efficient machine. Every time. Efficiency is not a spec-sheet nicety, it is the number that decides how many halvings you survive.

Write down the landed cost. The $1,701 machine was a $2,676 commitment once freight, import duty, customs and setup were in — 57% more than the sticker — and the payback clock runs on the larger number. Measured against it, this machine has now covered itself 1.2× over.

Do not annualise a pre-halving day rate. If you had taken that $7.07 a day and multiplied it by 365 you would have expected $2,580 in year one alone. The whole run has produced $2,612 at the prices of the day — a good result, and less than half the pace the months before the halving implied.

And buy the efficiency you can afford. This machine worked because 6¢ and then 3.9¢ carried it, not because 23 J/TH was ever good. The same run on a 15 J/TH machine would have made the same coins for close to half the electricity — and would have had far more runway at 6¢ before it ever needed to move.

For what we think of the hardware itself — the failure rates, the board revisions, what breaks — read the Bitmain Antminer S19K Pro review. For why we think about any of these machines the way we do, machines are the roof, not the building.

Which machines this covers

The other side of this machine

Bitmain Antminer S19K Pro review — Three years in, it has covered its own hardware and is still mining. That works on cheap power. What you are buying is 23 J/TH and a hashboard failure rate operators put in the single digits inside six months.

Disclosure

Firsthand Bitcoin sells and hosts mining hardware, including this machine. No manufacturer, distributor or affiliate programme paid for or reviewed this page and we take no commission on the links above. Historical figures are computed from daily bitcoin price and network hashprice, each day valued at its own prices. Nothing here is investment advice.