One box, 1.35 petahashes per second, and a 20-kilowatt appetite. Here is the honest arithmetic on the biggest single Bitcoin miner in the OneMiners range.
- 1,350 TH/sHashrate
- 20,000 WPower draw
- 14.81 J/THEfficiency
- $14,559OneMiners price
Key takeaways
- ✓ Highest single-unit output OneMiners sells at 1.35 PH/s, grossing an estimated $51.52 a day — but drawing 480 kWh a day to do it.
- ✓ At the OneMiners Nigeria rate of $0.048/kWh the estimated margin is $28.48 a day. At a typical $0.12/kWh home tariff the same unit loses about $6 a day.
- ✓ Break-even electricity price is roughly $0.107/kWh, so this miner only makes sense on genuinely cheap, reliable power.
Most reviews of high-end mining hardware stop at the headline number. The MicroBT Whatsminer M79S has a very good headline number: 1.35 PH/s, or 1,350 TH/s, from a single chassis. Nothing else on the OneMiners shelf produces more hashing in one box.
But a headline number is only half a sentence. The other half is 20,000 watts — twenty kilowatts of continuous draw, which is roughly what fifteen average homes use at the same time. This article is about what happens when you put both halves together, because that is where the M79S becomes either an excellent purchase or an expensive mistake.
What the M79S is, and who builds it
MicroBT is one of two manufacturers that genuinely matter at the top of the Bitcoin mining market, and the Whatsminer line has a long reputation for running hard for a long time without drama. The M79S is a hydro unit: coolant is pumped through a cold plate against the chips instead of fans pushing air across them. At 20 kW there is no realistic air-cooled alternative — the heat simply cannot be moved fast enough.
The unit is listed on the OneMiners store at $14,559, checked on 8 September 2026. That is worth sitting with for a moment. It is roughly half the immediate-supply price of Bitmain's flagship while producing about 16 per cent more hashing. Purely on dollars per terahash bought, the M79S is one of the strongest offers in the catalogue.
OneMiners also stocks lower-binned versions of the same design at 1.048 PH/s and 920 TH/s. Those are the same architecture running at reduced clocks and reduced power, which changes the arithmetic below but not the argument.
Raw output versus efficiency: the trade you are actually making
Efficiency is measured in joules per terahash, or J/TH — how much electricity the miner spends to do one trillion attempts at the Bitcoin puzzle. Lower is better. The M79S lands at 14.81 J/TH.
That figure is respectable but it is not class-leading. Bitmain's current flagship reaches 9.50 J/TH, which means it spends about a third less electricity for the same amount of hashing. On paper that sounds like a small gap. In practice it is the whole argument, because it changes the electricity price at which each miner stops making money.
The M79S breaks even at roughly $0.107 per kWh. Above that rate it earns less than it costs to run. A 9.50 J/TH unit keeps going up to about $0.167 per kWh. If you have very cheap, reliable power, that difference barely matters and the M79S wins on volume. If you do not, it matters enormously.
What it earns, and how the estimate is built
Your mining revenue is your share of the network's computing power multiplied by what the network pays out. The industry shorthand for this is hashprice — the estimated dollars that one petahash per second earns in a day.
On 8 September 2026, with Bitcoin near $78,450, network hashrate around 925 EH/s and difficulty at 127.45T, hashprice worked out at about $38.16 per PH/s per day. The M79S contributes 1.35 PH/s, giving an estimated gross revenue of about $51.52 a day — the highest single-unit figure in this catalogue.
Now the other half. At 20,000 W the unit consumes 480 kWh every day. At the OneMiners Nigeria premium rate of $0.048 per kWh that is $23.04 of electricity, leaving an estimated $28.48 a day. At a typical residential rate of $0.12 per kWh the electricity alone costs $57.60 — more than the miner earns. The same hardware that clears nearly thirty dollars a day in the right place loses roughly six dollars a day in the wrong one.
How it compares with three other OneMiners Bitcoin miners
The Antminer S23 Hyd 3U earns less gross revenue but keeps more of it, because 9.50 J/TH costs far less to feed. The SealMiner A4 Ultra Hyd earns considerably less in absolute terms yet costs $9,999 and matches Bitmain on efficiency, which makes it the sensible pick for anyone with a smaller budget or a higher power price.
The pattern is consistent. Gross revenue tracks hashrate; net margin tracks efficiency. Which one you should optimise for depends entirely on what you pay for electricity, and that is a question about your site, not about the hardware.
Infrastructure: 20 kW is a commercial installation
This is the section to read before you buy. A 20 kW hydro unit is industrial plant, not equipment you site by preference.
- Power. Twenty kilowatts continuous, on three-phase commercial supply with appropriately rated protection. No domestic installation can carry this, and the standing charges alone on a suitable commercial connection are significant.
- Coolant loop. A pump, a dry cooler or heat exchanger sized for 20 kW of rejection, filtration, and a coolant that will not corrode the plate. Budget for it separately; none of it ships with the miner.
- Heat. Every watt comes back out as heat. Twenty kilowatts is a serious thermal load that has to leave the building, which in warm climates means the cooling plant itself consumes meaningful extra power.
- Noise. The chassis is quiet because there are no high-speed fans in it, but the pumps and outdoor cooler are not. This belongs in a plant room or a container, never in a home.
- Water discipline. Sealed loops still need monitoring for pressure, temperature and leaks. A leak across live electronics at this power level is the failure that ends a deployment fastest.
Why your electricity price decides the outcome
Electricity is typically 75 to 85 per cent of the ongoing cost of running a Bitcoin miner, and the M79S sits at the extreme end of that rule because of its appetite. It consumes 480 kWh a day — nearly double what a 9.50 J/TH flagship uses for a comparable job.
Look at the top two bars. At $0.15 and $0.12 per kWh there is no payback at all, because there is no margin to pay anything back with. From $0.079 per kWh downwards the picture changes quickly, and at the cheapest hosting rates the unit clears its purchase price in a little over a year.
This is the clearest illustration in this whole series of why hosting is not a nicety for high-power hardware. The M79S is not a bad miner at $0.12 per kWh. It is simply the wrong miner for $0.12 per kWh, and no amount of good hardware fixes a bad power price.
Who should buy the M79S
- Operators with genuinely cheap power. Below about $0.06 per kWh the M79S is one of the best value purchases available, because you are buying hashrate at a very low cost per terahash.
- Anyone constrained by rack slots rather than kilowatts. If you have power headroom and limited space, one box producing 1.35 PH/s is hard to beat.
- Hosted buyers. In a facility with hydro infrastructure and sub-$0.05 power already in place, the efficiency penalty is manageable and the volume advantage is yours to keep.
- Not for home or high-tariff sites. If you pay retail electricity, this unit will cost you money. Choose a more efficient miner instead.
Strengths and weaknesses
Strengths
- Highest single-unit output in the OneMiners Bitcoin range at 1.35 PH/s.
- Excellent cost per terahash purchased at $14,559.
- MicroBT hydro platforms have a strong track record for sustained running.
- Lower-binned 1.048 PH/s and 920 TH/s versions available if you want the design at less power.
Weaknesses
- 14.81 J/TH is mid-tier efficiency, giving a low break-even price of about $0.107 per kWh.
- Twenty kilowatts of continuous draw rules out most sites entirely.
- Loses money at typical residential and light-commercial electricity prices.
- Coolant plant and 20 kW heat rejection are substantial extra costs.
Hosting or self-hosting for a 20 kW miner
For this unit the question almost answers itself. Building your own site means a commercial three-phase connection, a 20 kW coolant loop, heat rejection, network, monitoring and someone to respond when a pump fails at three in the morning. Then you still pay commercial electricity rates that in most of Europe and North America start above the miner's break-even price.
OneMiners runs 20 sites with roughly 2,163 MW of contracted capacity at an average of about $0.0480 per kWh, with 98 per cent or better average uptime. The cheapest standard premium rate is Nigeria at $0.048 per kWh; the floor across the network is $0.045 per kWh on Georgia's seven-year prepaid contract. Hydro-ready infrastructure, on-site repair, automated restart monitoring and a seven-year hardware warranty come with the site.
What that looks like over the long term
Extending today conditions gives a rough sense of scale. At $0.048 per kWh the estimated margin of $28.48 a day is about $10,400 a year, or roughly $31,200 over three years — more than twice the $14,559 hardware cost. At $0.12 per kWh the three-year figure is negative.
Treat the three-year number as an upper bound rather than a forecast. Network difficulty has risen over almost every multi-year window in Bitcoin history, and rising difficulty shrinks every existing miner share of the reward. A rising Bitcoin price can offset that, and has before, but nobody can promise it will. What cheap electricity buys you is the room to keep running while you find out.
The arithmetic on this specific unit is stark. At $0.048 per kWh the estimated margin is $28.48 a day, about $10,400 a year. At $0.12 per kWh it is negative. That is not a difference in return; it is the difference between an asset and a liability, produced entirely by the price of electricity. It is arithmetic, not marketing.
Frequently asked questions
How much electricity does the Whatsminer M79S use?
About 20,000 W continuously, which works out to roughly 480 kWh a day or 175,000 kWh a year. At $0.048 per kWh that is about $23 a day; at $0.12 per kWh it is about $58 a day. The power bill, not the purchase price, is the dominant cost of owning this Bitcoin miner.
Is the M79S more profitable than the Antminer S23 Hyd 3U?
It grosses more — an estimated $51.52 a day against $44.27 — but it also burns far more power. After electricity at $0.048 per kWh the S23 Hyd 3U comes out ahead at about $31.57 a day against $28.48. The M79S only wins on net margin when power is very cheap.
What is the break-even electricity price for the M79S?
Roughly $0.107 per kWh at current market conditions. Below that rate it earns a margin; above it, electricity costs more than the miner earns. This figure moves with Bitcoin's price and network difficulty, so treat it as a guide rather than a fixed line.
Can I run the M79S at home?
No. It needs 20 kW of continuous three-phase commercial power and a coolant loop sized to reject 20 kW of heat. Beyond the physical impossibility for most homes, residential electricity prices are above its break-even rate, so it would lose money even if you could plug it in.
Why does OneMiners sell 920 TH/s and 1.048 PH/s versions too?
They are the same platform running at lower clocks and lower power. Underclocked units are more efficient per terahash and easier to site, which suits operators with tighter power budgets. The 1.35 PH/s version is the maximum-output configuration.
How long until the M79S pays for itself?
At $0.048 per kWh, an estimated 17 months on hardware cost alone at current conditions. At $0.079 per kWh it stretches to around 35 months. At residential rates there is no payback, because there is no margin. All of these are estimates that move with the market.
Does hydro cooling make it more reliable than air cooling?
Generally yes, because chip temperatures stay steadier and there are no fan bearings to fail inside the chassis. The trade is that you inherit a water system: pumps, filters and pressure to monitor. Reliability shifts from the miner to the plant around it.
Work out your own numbers before you commit
The M79S rewards one thing above all others: cheap electricity. Take your rate per kilowatt-hour, multiply it by 480, and compare the result with an estimated $51.52 of daily revenue. If your power costs more than about $0.107 per kWh, the honest answer is that this is not your miner.
If the numbers do work, check current pricing, specification and availability on the Whatsminer M79S product page, and compare it with the rest of the range in the most profitable Bitcoin miners collection.
And if your power price is the problem rather than the hardware, hosting is the fix. OneMiners provides the three-phase supply, the coolant loop, the heat rejection, the monitoring and the repairs — you own the miner and keep what it mines.
Risk and profitability disclaimer
Every earnings figure in this article is an estimate, not a promise. Estimates were calculated on 2026-09-08 using a Bitcoin price of $78,450, a network hashrate of 925 EH/s, a difficulty of 127.45T and a resulting hashprice of about $38.16 per PH/s per day. All four of those inputs change constantly.
Mining revenue rises and falls with Bitcoin’s price, network difficulty, transaction fees, pool fees, your uptime, ambient temperature and the quality of your cooling. Costs rise and fall with electricity prices, hosting service fees, shipping, import duties and repairs. Nothing here is guaranteed, risk-free or always profitable, and none of it is investment advice.
Prices, specifications, batch dates and stock levels were taken from the OneMiners store on the date shown and can change without notice. Confirm the current figure on the product page before you buy. Manufacturer specifications carry their own tolerance, usually around plus or minus five per cent on both hashrate and power draw. Mine only with money you can afford to put at risk.
