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Machine review · Oct 28, 2026 · 4 min read
Whatsminer M74S+ review: 12 J/TH on air, a cheap coin at a high price per terahash
MicroBT's M74S+ is an air-cooled Whatsminer at 12 J/TH, the most efficient air machine in our store, and it asks a high price for each terahash. It makes a coin for less than the 13.5 and 15 J/TH machines, and at Argentina's 6¢ it still clears its power at half of today's hashprice.
MicroBT Whatsminer M74S+ (332 TH/s)
The bottom line
The M74S+ is MicroBT's air-cooled Whatsminer at 12 J/TH: 332 TH/s from 3,984 W in the bin we use here. In Argentina, at 6¢, it makes a bitcoin for about $40,400 of electricity and returns roughly 31% in its first year at today's price. At Nigeria's 3.9¢ the same coin costs about $26,300.
Bought in June 2026, once we held a price for it, it has mined and kept 0.0206 BTC for $767 of power in 129 days: $879 of cashflow against a $7,001 landed cost, 13% of the box so far, and it has not needed to move. Between now and the 2028 halving it has another 0.080 BTC in it, worth about $9,898 with bitcoin back at its previous high of $124,493: roughly 1.5× its hardware by the halving.
What you are buying is among the cheapest coins an air-cooled machine makes, at a price per terahash well above the older air machines. The S21 XP makes a coin in Argentina for about $45,400 and the S21 Pro for about $50,500, against this machine's $40,400, and they ask $11.55 and $8.61 a terahash against its $14.86.
Scores
| Criterion | Score | Why |
|---|---|---|
| Cashflow | 5/10 | Makes a bitcoin for about $40,400 of electricity at 6¢ and about $26,300 at 3.9¢, and returns roughly 31% in year one in Argentina. It has covered 13% of its hardware in 129 days and is on track for about 1.5× by the 2028 halving. The S21 Pro returns about 35% in year one because its box costs less per terahash. |
| Longevity | 7/10 | At 12 J/TH its line is $17.28 a petahash a day at 6¢ and $11.23 at 3.9¢. Half of today's hashprice, $17.97, is above both, so after the halving it still clears at 6¢ with 69 cents to spare. |
| Efficiency | 8/10 | The most efficient air-cooled machine we stock: the S21 XP runs 13.5 J/TH, the M60S++ 15.5 and the S21 Pro 15. Only the water machines are lower: the S23 XP Hyd at 8.9 and the S23 Hyd at 9.5. |
| Quality control | 5/10 | Scored as unknown rather than as good. We found no operator reports of the M74S+ in the field that we could cite, and the first price we hold for it is from April 2026. |
| Serviceability | 6/10 | Air-cooled, so it lives in Argentina, where we repair on site and bill the cost of the parts only. We could not open a maker page with warranty terms, so we score on our own repair terms. |
Efficiency and longevity count most, because they decide how many halvings a machine clears. Reliability is scored as unknown, not as good, so it holds the total down.
Buy it if
- Your power is at or below 6.2¢ and you plan past the 2028 halving. At 12 J/TH a petahash uses 288 kWh a day, so the machine's line is $17.28 at 6¢ and $11.23 at Nigeria's 3.9¢, and half of today's hashprice, $17.97, covers both.
- Your power is between 6.2¢ and 12.5¢ and you are buying hashrate for the run to the April 2028 halving. At $35.95 a petahash a day the machine clears its line at every rate up to 12.5¢.
- You want a cheap coin on air: about $40,400 of electricity in Argentina, against $45,400 for the S21 XP and $52,200 for the M60S++.
- You have, or are hosted at, a site that cools by air, such as ours in Argentina.
Walk away if
- You want the most hashrate for your money. The S21 XP asks $11.55 a terahash, the S21 Pro $8.61 and the M60S++ $9.45, against $14.86 here, and the S21 Pro returns about 35% in year one against this machine's 31%.
- Your power is above 12.5¢. At today's hashprice the machine does not clear its line there.
- Your power is between 6.2¢ and 12.5¢ and you plan to run past April 2028 at today's conditions held flat. In that band it clears today and not after the halving.
- You want a public failure record before you buy. We found no operator reports of the M74S+ that we could cite, so we score reliability as unknown.
12 J/TH on air, in four speed bins
The M74S+ is a Whatsminer from MicroBT's M7 line. Our store lists four bins: 316 TH/s from 3,950 W, 324 TH/s from 4,050 W, 330 TH/s from 4,125 W and 332 TH/s from 3,984 W. The first three run at 12.5 J/TH and the 332 TH/s bin at 12 J/TH. This review uses the 332 TH/s bin, and its figures are our store record: we could not open a maker spec page for the machine, so we leave out any dimension or weight the record does not hold.
It is air-cooled, which decides where it lives. A machine on air starts in Argentina, at 6¢ and 98.7% uptime, and crosses once to Nigeria's 3.9¢ when a year of figures says its power pays better there. The older M70S has its own review at 13.5 J/TH; this one is a step down the efficiency table from it.
The price per terahash is the high one
The first price we hold for the 332 TH/s unit, on 24 April 2026, was $14.99 a terahash. A purchase once it settled, in June 2026, cost $5,161. It is $4,933 today, $14.86 a terahash, and that is the lowest we have held for it. Since April it has stayed between $14.86 and $15.88 a terahash, so the box has barely moved in six months.
Against the air machines it competes with, it asks the most. The S21 XP is $11.55 a terahash at 13.5 J/TH, the SealMiner A2 Pro $12.18 at 14.9, the S21 Pro $8.61 at 15 and the M60S++ $9.45 at 15.5. A price per terahash settles to where a machine's efficiency, its maker and its age put it, and the guide to what a miner costs all-in shows what sits on top of the box.
It makes the cheaper coin, and the S21 Pro makes the bigger first year
In Argentina, at 6¢, the M74S+ makes a bitcoin for about $40,400 of electricity today, against a bitcoin price of $81,447. At Nigeria's 3.9¢ it makes one for about $26,300, with Nigeria's lower uptime already counted. The S21 XP makes one in Argentina for about $45,400, the S21 Pro for about $50,500, the A2 Pro for about $50,200 and the M60S++ for about $52,200.
In its first year it returns about 31% in Argentina and 31% in Nigeria at today's price and difficulty. The S21 Pro returns 35% in Argentina and the S21 XP 33%. The two figures answer different questions. Year one rewards a cheap box, and the S21 Pro's is cheaper per terahash. The cost of a coin rewards efficiency, and here this machine wins.
Over its run since June 2026, electricity has averaged about $37,300 a coin, a lifetime average over 129 days at 6¢. The figure to plan on is today's.
Where the halving puts it
A machine's line is the hashprice at which it stops covering its own power. At 12 J/TH a petahash uses 288 kWh a day: $17.28 at 6¢, and $11.23 at Nigeria's 3.9¢. On our hashprice chart, network hashprice was $35.95 a petahash a day on 27 October, so the M74S+ clears the 6¢ line with $18.67 to spare and Nigeria's with $24.72.
Neither line has been crossed since the 2024 halving. Hashprice reached a low of $27.74 on 6 June 2026, $10.46 above the 6¢ line for this machine. The count for a 19 J/TH machine shows how a dearer line has fared.
The 2028 halving halves the coins a petahash earns. At today's price and difficulty that puts hashprice near $17.97, over the 6¢ line by 69 cents and over Nigeria's by $6.74. That is today's conditions held flat, not a forecast: it is why every projection we publish assumes the old high returns. The guide to efficiency and halvings shows where the line sits at every J/TH. At 12 J/TH, 6.2¢ is about the highest power rate that still clears across the halving, and a machine on cheaper power has far more room.
At 12 J/TH, half of today's hashprice still covers Argentina's power with 69 cents to spare.
What a fault costs you here
We looked for operator threads on the M74S+ and found none we could stand behind. The first price we hold for it is from April 2026, so the machine has months in the field and not years, and it is scored as unknown on quality control rather than as good. That is a score, not a warning.
What a fault costs is the part that matters. In Argentina we repair on site and bill the cost of the parts only, and an air machine is serviced where it hangs: a failed hashboard is a line item, not a catastrophe. The guide to cooling explains what air changes.
Our two cents
The M74S+ is the efficient end of the air-cooled range at a price to match. It clears its power at 6¢ today with room to spare, it fits the Argentina site we already run, and the one move it will make, to Nigeria, takes a coin from about $40,400 to about $26,300.
If the aim is the biggest first year per dollar of box, the S21 Pro returns about 35%. If the aim is a cheap coin on air, this is the one. The figure below ranks what beats it on cost per coin and then on first-year return, in stock today.
- Bitmain Antminer S23 Hyd (563 TH/s) — 9.5 J/TH, In stock, $33,180 of electricity per bitcoin, 24% year one
- Bitmain Antminer S23 XP Hyd (600 TH/s) — 8.9 J/TH, Pre-order, $31,083 of electricity per bitcoin, 23% year one
- Bitmain Antminer S23 Hyd 3U (1,160 TH/s) — 9.5 J/TH, Sold out, $32,561 of electricity per bitcoin, 22% year one
Which machines this covers
- MicroBT Whatsminer M74S+ (332 TH/s)
- MicroBT Whatsminer M74S+ (330 TH/s)
- MicroBT Whatsminer M74S+ (324 TH/s)
- MicroBT Whatsminer M74S+ (316 TH/s)
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.