Antminer S21 Pro, S21 XP or S21 Hydro: which Bitcoin miner for Europe?
The Antminer S21 family now covers most new Bitcoin mining in Europe. But between the S21 Pro, the S21 XP and the S21 Hydro, the right choice depends on three things: your electricity price, your electrical installation and where the machine will run. Here is our comparison, with the numbers we use with our customers.
The three machines
| S21 Pro | S21 XP | S21 Hydro | |
|---|---|---|---|
| Hashrate | 245 TH/s | 270 TH/s | 319 TH/s |
| Power | ≈ 3500-3650 W | 3650 W | 5100 W |
| Efficiency | 15 J/TH | 13.5 J/TH | 16 J/TH |
| Cooling | Air | Air | Water |
| Noise | 75 dB | 75 dB | ≈ 50 dB |
| Power supply | 230 V, 20 A line | 230 V, 20 A line | Three-phase 380-415 V |
| Product page | S21 Pro | S21 XP | S21 Hydro |
S21 Pro: the best price per TH
The S21 Pro is the machine we sell most. At 15 J/TH it is 30 % more efficient than an S19k Pro, and its price per TH remains the lowest in the family. It suits a miner with a dedicated 20 A line, a room where 75 dB bothers nobody, and electricity below roughly 0.12 €/kWh (business contract, off-peak, solar, hosting).
S21 XP: when electricity is expensive
The S21 XP costs more per TH, but its 13.5 J/TH saves 10 % of electricity per hash. On a machine that uses 32,000 kWh a year, 10 % is 3,200 kWh, almost €1,000 a year at 0.30 €/kWh. The more expensive your electricity, the faster the XP pays for itself; above 0.10 €/kWh it is usually the better choice. It is still air-cooled: same noise and heat constraints as the Pro.
S21 Hydro: silence and reusable heat
The S21 Hydro has no fans: it dumps its 5 kW into a water loop. The result is 50 dB instead of 75, and heat at 40-55 °C that can go into underfloor heating, a buffer tank, a pool or a greenhouse. It is the machine for electricity and heat recovery projects. It does however need three-phase 380 V and a hydraulic installation: a hydro kit or an Antrack cabinet, which we supply and configure.
The break-even point, in practice
At the time of writing, with current network parameters, the maximum electricity cost to break even is around 0.10 to 0.12 €/kWh for an S21 Pro, and slightly more for an S21 XP. These figures move with the Bitcoin price and the difficulty: check them with your tariff in our profitability calculator before buying. If your tariff is higher, two solutions: cut the electricity cost (solar, off-peak) or host the machine with us in the USA through our hosting offer.
Our recommendation
- Cheap electricity, room available: S21 Pro, best price per TH.
- Expensive electricity: S21 XP, efficiency pays.
- Need silence or heat: S21 Hydro with a hydro kit.
- No 20 A line: S21 151 TH, which runs on a 16 A socket.
All our machines are tested before shipping, delivered across Europe with the manufacturer warranty, and we install our HappyMining firmware (overclocking, undervolting, autotune) free of charge on request. See all our Bitcoin miners.