Antminer S21 XP: Specs, Solo-Mining Odds, and How to Rent One by the Hour
Last updated · By Galaxy Mind
The Antminer S21 XP is Bitmain's air-cooled Bitcoin miner, rated at about 270 TH/s while drawing about 3,645 W, which works out to 13.5 J/TH. It mines SHA-256 coins and needs a 220 to 277 V circuit. If you only want to try one, you can rent a US-based S21 XP's hashrate by the hour on our rent page.
Rent an S21 XP by the hour →S21 XP specs at a glance
| Maker | Bitmain |
|---|---|
| Algorithm | SHA-256 |
| Coins | BTC, BCH, BSV |
| Hashrate | 270 TH/s typical (±3%) |
| Power at the wall | 3,645 W at 25 °C inlet air (±5%) |
| Efficiency | 13.5 J/TH at 25 °C inlet air (±5%) |
| Input voltage | 220 to 277 V AC, 50 to 60 Hz |
| Input current | 20 A, single phase |
| Power supply rating | 4,000 W |
| Cooling | Air (fans) |
| Noise | 76 dBA at maximum fan speed |
| Network | RJ45 Ethernet 10/100M |
| Size without box | 449 × 219 × 293 mm |
| Net weight | 18.7 kg |
| Operating temperature | -20 to 45 °C |
| Operating humidity | 10 to 90% RH, non-condensing |
Source: Bitmain's S21 XP Specifications page. Hashrate and power are typical values. Bitmain says hashrate can vary by ±3% and power by ±5%. Read Bitmain's spec page.
S21 XP vs S21 Pro vs S21 XP Hyd
| Model | Hashrate | Power | Efficiency | Cooling | Supply |
|---|---|---|---|---|---|
| S21 XP | 270 TH/s | 3,645 W | 13.5 J/TH | Air | 220 to 277 V, single phase |
| S21 Pro | 234 TH/s | 3,510 W | 15 J/TH | Air | 220 to 277 V, single phase |
| S21 XP Hyd | 473 TH/s | 5,676 W | 12.0 J/TH | Water | 380 to 415 V, three phase |
Air-cooled figures are at 25 °C inlet air. The hydro figures are at 35 °C inlet coolant. All three come from Bitmain's own specification pages.
Which one is more efficient?
The S21 XP uses about 10% less energy per terahash than the S21 Pro, and it hashes about 15% faster from a similar power draw. Lower J/TH means more hashing for every kilowatt-hour you pay for.
Air vs hydro: why it matters for home miners
The S21 XP Hyd is the water-cooled sibling, rated at 473 TH/s and 12.0 J/TH. It runs on three-phase power and a coolant loop, so it belongs in a mining site, not a garage. If a search result mixes the two, the 270 TH/s figure is the air-cooled S21 XP.
Is an S21 XP worth running?
Whether an S21 XP pays for its power depends on two numbers that move every day: what you pay for electricity and the live hashprice. Nobody can promise the answer ahead of time, so here is how to work it out yourself.
The three numbers that decide it
- Hashprice: what one unit of hashrate is paid each day across the network. It moves with the value of bitcoin, fees and network difficulty.
- Power cost: one S21 XP uses about 87.5 kWh a day (3.645 kW for 24 hours). Multiply that by what you pay per kWh.
- Uptime: a miner that is off, too hot or misconfigured hashes nothing. Count the hours it actually runs.
Daily result = hashrate × hashprice − power cost. Plug in today's numbers rather than anyone's forecast.
Where to get today's numbers
- mempool.space mining dashboard · Live network hashrate and difficulty.
- Hashrate Index · Live hashprice as a data source.
Solo-mining odds for one S21 XP
One S21 XP is a tiny slice of the whole Bitcoin network, so its chance of finding a block alone is small. The figures below use today's network hashrate from mempool.space and update through the day.
Loading live odds
Try other sizes and time windows in the solo mining calculator, which starts at 270 TH/s.
Why most solo attempts find nothing, and why that's normal
Each block goes to whoever finds a valid hash first. Your chance at each block is your hashrate divided by the network's, and a single machine is well under one millionth of the total. Many solo miners run for months and find nothing. Treat a block as a bonus, never a plan.
Rent an S21 XP instead of buying one
Yes. Galaxy Mind rents professionally hosted, US-based S21 XP hashrate in 270 TH/s chunks, from 3 hours up to 7 days. You choose the pool and the payout address, and we never hold your coins.
What you get
- Hashrate in 270 TH/s chunks, which is one S21 XP each.
- Rentals from 3 hours up to 7 days.
- Your pool and your payout wallet. We never touch the coins and never ask for ID.
- US-based, professionally hosted machines with steady power and cooling.
How to rent in three steps
Pick how much hashrate you want on our rent page, set your pool and payout address, and choose your hours. The step-by-step guide walks through every click, and AI agents have their own agent guide.
Checking delivery
- Watch the live hashrate graph for each unit you rent.
- Check the accepted shares on your own pool's dashboard.
- If a unit underdelivers, the rental marketplace's own refund rules apply, and you can see them before you pay.
Rent vs buy, in one table
| Topic | Buy one | Rent one |
|---|---|---|
| Upfront cost | You pay for the machine before it hashes. | You pay for the hours you choose. |
| Power | About 3.6 kW on a 220 to 277 V circuit, around the clock. | None at your place. |
| Noise and heat | Up to 76 dBA, with the heat of a large space heater. | Neither reaches your home. |
| Resale | You own hardware you can sell later. | Nothing to sell, nothing to store. |
| Flexibility | Runs as long as you keep it powered. | From 3 hours up to 7 days at a time. |
How loud and hot is an S21 XP at home?
Bitmain rates the S21 XP at 76 dBA with the fans at full speed, which is loud enough to fill a room. It also turns about 3.6 kW into heat and needs a dedicated 220 to 277 V circuit. Renting keeps the noise, the heat and the wiring out of your house.
Prefer a machine on your own desk? These shops sell home-mining hardware for bitcoin and are listed in our directory. Solo Satoshi, Bitaxe Shop, FutureBit. See every hardware shop that takes bitcoin.
Antminer S21 XP FAQ
What is the Antminer S21 XP?
It is Bitmain's air-cooled SHA-256 Bitcoin miner, rated at about 270 TH/s and 13.5 J/TH. It draws about 3,645 W at the wall and runs on 220 to 277 V.
What is the hashrate of the S21 XP?
Bitmain rates it at 270 TH/s typical, give or take 3%. Galaxy Mind rents hashrate in the same 270 TH/s chunks.
How much power does the S21 XP use?
About 3,645 W at the wall with 25 °C inlet air, give or take 5%. That is about 87.5 kWh over a full day.
What is the difference between the S21 XP and the S21 Pro?
The S21 XP is rated at 270 TH/s and 13.5 J/TH, and the S21 Pro at 234 TH/s and 15 J/TH. Both are air-cooled and run on single-phase 220 to 277 V.
Is the S21 XP Hyd the same machine?
No. The S21 XP Hyd is water-cooled, rated at 473 TH/s and 12.0 J/TH, and needs three-phase 380 to 415 V power and a coolant loop.
What are the odds one S21 XP finds a block solo?
Small. Your chance at each block is your hashrate divided by the network's. This page and the solo mining calculator work it out live for 270 TH/s over a day and a week.
Can I rent an S21 XP instead of buying one?
Yes. Galaxy Mind rents US-based S21 XP hashrate in 270 TH/s chunks for 3 hours up to 7 days. You set your own pool and payout address.
Do I need KYC to rent?
Not with us. We never ask for ID. The rental marketplace has its own account rules, and those still apply.
Try an S21 XP without buying one
See which 270 TH/s chunks are free right now, point them at your own pool, and keep whatever they find.