What is the Antminer S21 family?
Definition · Antminer S21
A range of SHA-256 Bitcoin mining machines from Bitmain, launched in late 2023. The original S21 uses Bitmain’s BM1368 chip; the S21 Pro moved to the BM1370. Later models add more hashboards, liquid cooling or both.
9
Models on this page
manufacturer-rated, September 2026
11 to 17.5
J/TH range
lower is better
200 to 480
TH/s range
per machine
$0.0403
Per TH/s per day
live hashprice
The name tells you the variant: Pro and XP are faster, more efficient versions, + is a higher-hashrate version, Hyd is hydro (liquid) cooled and Imm is built for immersion. New to mining machines? Start with what a mining machine is.
How do the S21 models compare?
| Model | Cooling | TH/s | Watts | J/TH | Noise |
|---|---|---|---|---|---|
| S21 | Air | 200 | 3,500 | 17.5 | not published |
| S21 Pro | Air | 234 | 3,510 | 15 | 76 dBA |
| S21 XP | Air | 270 | 3,645 | 13.5 | 76 dBA |
| S21 Hyd | Hydro | 335 | 5,360 | 16 | not published |
| S21+ Hyd | Hydro | 358 | 5,370 | 15 | not published |
| S21 XP Hyd | Hydro | 473 | 5,676 | 12 | not published |
| S21 XP+ Hyd | Hydro | 480 | 5,280 | 11 | not published |
| S21 Imm | Immersion | 239 | 3,824 | 16 | not published |
| S21 XP Imm | Immersion | 300 | 4,050 | 13.5 | not published |
The S21 Imm is also sold as a 301 TH/s version at 18.5 J/TH. Only models whose specs Bitmain publishes are listed. This is a spec comparison, not a purchase recommendation; the hardware comparison puts them next to MicroBT and Canaan machines.
Air, hydro or immersion: what’s the difference?
Air
S21, S21 Pro, S21 XP
Big fans push air through three hashboards. Simple to run, very loud, and the heat goes wherever the air goes.
Hyd
Hydro (liquid) cooled
Coolant runs through cold plates to a dry cooler outside. Quieter at the machine and more hashrate per box. Bitmain’s S21 XP Hyd sheet says it won’t start with inlet water below 20 °C.
Imm
Immersion
The machine sits in a tank of non-conductive fluid that carries the heat away. Quiet, dense, and the tank is its own project.
Liquid cooling keeps the chips cooler, so the same design can run harder. That’s why hydro models reach the highest hashrate in the family. It also makes the heat easier to reuse, from greenhouses to district heating.
Why does J/TH matter so much?
J/TH is the energy a machine uses for a trillion hashes. Every machine earns the same per TH/s, so what separates them is how much electricity that TH/s costs. Here’s how far it has come since the S19.
Energy per terahash, S19 generation vs S21
The Antminer S19 needed 34 joules per terahash. The Antminer S21 XP needs 13.5. Same work, 60% less power. As the network grows and each TH/s mines less, the older machines are the first to cost more than they make.
What electricity price does an S21 break even at?
Break-even electricity price, at live hashprice
Below its break-even price a machine mines more than its electricity costs. Above it, every hour runs at a loss. The hashprice guide explains what moves that number.
How much power and noise does an S21 need?
3.6 kW
S21 XP draw
nonstop, rated
87 kWh
Per day
running nonstop
76 dBA
Air-cooled noise
S21 Pro and XP, rated
5.3 to 5.7 kW
Hydro models
rated draw
A 3.5 kW load running around the clock is at or over the limit of a normal socket circuit, so it needs its own circuit fitted by an electrician. The noise needs a garage, a shed or a data centre. The mining at home guide covers wiring, noise and using the heat.
What does the estimate leave out?
The machine’s price
Plus shipping and import duty. It also loses value as newer models arrive.
Pool fees
Usually a few percent of what the machine mines.
Hosting or cooling gear
A hosting rate, dry coolers, pumps or immersion tanks.
Downtime and repairs
Reboots, failed hashboards, heat waves and curtailment.
Network growth
Hashrate tends to rise, so each TH/s mines a little less over time.
The halving
Every four years the block subsidy halves, and so does most of the gross.
For the full picture read is Bitcoin mining profitable. For the lottery side of mining with one machine, see solo mining odds.
Can you mine without buying a machine?
Yes. In the CloudMineCrypto app you mine for free with the free plan, ads, games, offers and daily check-ins, and your BTC balance grows while your plans run. No machine, no 76 dB fans, no power bill, and you withdraw to your own wallet, Lightning included. Want more speed? Add an optional paid plan.
Good to know: rewards are estimates, move with the network and aren’t guaranteed. A plan doesn’t give you ownership of, or a share in, any specific hardware or pool. Terms apply.
Frequently asked questions
What is the hashrate of the Antminer S21?
Bitmain rates the original S21 at 200 TH/s on 3,500 W (17.5 J/TH). Later models go higher: the air-cooled S21 XP is rated at 270 TH/s, and the hydro-cooled models reach up to 480 TH/s.
Which S21 model is the most efficient?
On Bitmain’s ratings, the Antminer S21 XP+ Hyd at 11 J/TH, as of September 2026. Efficiency decides the highest electricity price at which a machine still covers its power.
What is the difference between S21 Hyd and S21 Imm?
Hyd (hydro) models pipe water-based coolant through plates on the chips to an outside cooler. Imm (immersion) models sit fully submerged in a non-conductive fluid in a tank. Both are quieter at the machine and pack more hashrate per box than air cooling.
Is the Antminer S21 profitable?
It depends on your electricity price, the machine’s price and the network, and it changes daily. The calculator at the top shows today’s estimated gross against power at your tariff and the break-even price. It excludes the machine’s cost, fees and downtime.
How loud is an Antminer S21?
Bitmain rates the air-cooled S21 Pro and S21 XP at 76 dBA, about a vacuum cleaner running nonstop. Not something to keep in a living space.
Can I run an Antminer S21 at home?
The air-cooled models draw about 3.5 kW nonstop and are very loud, so they need a dedicated circuit and a garage or shed. Hydro and immersion models need plumbing or a tank. See the guide to mining at home.
Sources and further reading
- Antminer S21 specifications · Bitmain (manufacturer)
- Antminer S21 Pro specifications · Bitmain (manufacturer)
- Antminer S21 XP specifications · Bitmain (manufacturer)
- Antminer S21 Hyd specifications · Bitmain (manufacturer)
- Antminer S21+ Hyd specifications · Bitmain (manufacturer)
- Antminer S21 XP Hyd specifications · Bitmain (manufacturer)
- Antminer S21 XP+ Hyd specifications · Bitmain (manufacturer)
- Antminer S21 Imm specifications · Bitmain (manufacturer)
- Antminer S21 XP Imm specifications · Bitmain (manufacturer)
- Antminer S19 XP specifications (earlier generation) · Bitmain support (manufacturer)
- Antminer S19j Pro specifications (earlier generation) · Bitmain support (manufacturer)
- bitaxeSupra and bitaxeGamma READMEs (which chip each S21 uses) · Bitaxe project (GitHub)
Live figures on this page come from the CloudMineCrypto API or from the public blockchain data services named next to them, refresh on a schedule, and are labelled where they appear. This guide is educational and not financial advice. CloudMineCrypto is not an investment product; rewards in the app are estimates and aren’t guaranteed.
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