Antminer S21 vs S21+ vs S21 Pro vs S21 XP: differences and revenue

The difference between the Antminer S21, S21+, S21 Pro and S21 XP lies mainly in efficiency: from 17.5 J/TH for the base S21 to 13.5 J/TH for the S21 XP and 11–12 J/TH for the water-cooled XP versions. The hashrate of the air-cooled versions is similar (200–270 TH/s), so what matters is how much you pay for electricity. At today's difficulty and exchange rate, the S21 pays off up to an electricity price of 2.0 Kč/kWh, the S21 Pro up to 2.3 Kč/kWh and the S21 XP up to 2.6 Kč/kWh.

Summary

• S21 (2023) – the base of the series, 200 TH/s and 17.5 J/TH. Today it only makes sense with very cheap electricity.
• S21+ and S21++ – an improved air-cooled version with 216–235 TH/s and 16–16.5 J/TH.
• S21 Pro – the newer BM1370 chip and 15 J/TH efficiency, 14% better than the S21.
• S21 XP – the most efficient air-cooled S21 (13.5 J/TH). Hydro and immersion XP versions go down to 11–13.5 J/TH.
• Hydro versions (Hyd) have higher hashrate and noise of around 50 dB, but need a water loop and three-phase power.

What the +, Pro, XP, Hyd, Imm and e designations mean

• + and ++ – an improved version of the same design with higher hashrate and slightly better efficiency.
• Pro – a newer chip generation (BM1370 instead of the BM1368 in the base S21) and significantly better J/TH.
• XP – the top efficiency class in the series.
• Hyd – water cooling. Higher hashrate in a single machine, lower noise, heat that can be used for heating.
• Imm – a version for immersion cooling, i.e. submersion in a non-conductive liquid.
• e – a variant with slightly worse efficiency than the corresponding model without the “e”. In our range the difference is roughly 1 J/TH (e.g. S21e XP Hyd 13 J/TH vs 12 J/TH for the S21 XP Hyd).
• 3U – a rack-mount design three units high, for data centres.

S21 series specifications according to the manufacturer

The table shows the nominal values Bitmain stated when the models were launched. Units on sale differ by hashrate class and therefore power draw.

The S21+ is also sold in 225 and 235 TH/s classes. The S21++ designation is used for newer units with efficiency of around 16 J/TH. The alternative firmware Braiins OS lists it as a separate model.

How much the S21 variants earn today

For the calculation we take machines from our range with their actual hashrate and power draw. Revenue = hashrate × 0,84 Kč per 1 TH/s per day. Electricity is calculated at 1,13 Kč/kWh, the cheapest location in our hosting. All amounts apply at today's difficulty and exchange rate, as of 18 October 2026.

The “Pays off up to” column shows the electricity price at which the machine stops making money. You calculate it as 0.84 Kč ÷ (J/TH × 0.024). It does not depend on the machine's hashrate, only on its efficiency – which is why two machines with the same J/TH have the same threshold even if one earns twice as much. We explain J/TH in the article on ASIC power consumption and efficiency.

Differences point by point

S21 vs S21+

The S21+ adds 8–17% hashrate (216–235 TH/s instead of 200 TH/s) and reduces consumption per TH/s from 17.5 to 16.5 J/TH, and to 16 J/TH for the S21++. The case measures 400 × 195 × 290 mm and has four 140 mm fans.

S21+ vs S21 Pro

The hashrate is almost the same (around 234–245 TH/s), but the S21 Pro has a newer chip and 15 J/TH efficiency. At the same hashrate it saves roughly 8 kWh a day. In hosting at 1.13 Kč/kWh that is about 9.50 Kč a day, or roughly 3,500 Kč a year per machine at today's electricity price.

S21 Pro vs S21 XP

The S21 XP is the most efficient air-cooled S21 (13.5 J/TH, 270 TH/s). The profitability threshold moves from 2.3 to 2.6 Kč/kWh, so the XP will keep making money longer as network difficulty continues to rise.

Air vs Hyd and Imm

Air-cooled versions run at around 75 dB, water-cooled ones at around 50 dB. A hydro machine, however, needs a three-phase 380–415 V connection, a pump and a radiator. Immersion versions run submerged in tanks of liquid and cannot be operated on their own.

Which model for whom

• S21 / S21 151 TH/s – for those with electricity below 2 Kč/kWh who want the lowest purchase price. The profitability margin is small.
• S21+ / S21++ – an air-cooled machine for a farm or hosting when the S21 Pro is not available.
• S21 Pro / Pro+ – the most sensible choice among air-cooled machines for hosting: better J/TH, same infrastructure.
• S21 XP Imm – for operations with immersion cooling. 13.5 J/TH efficiency and quiet operation in the tank.
• S21+ Hyd, S21e XP Hyd – for data centres with a water loop or for ASIC miner hosting. The heat can be used for heating.

No S21 is suitable for the home: 75 dB is as loud as a vacuum cleaner, and a power draw above 3.5 kW requires a dedicated circuit. At normal household electricity prices it would also lose money.

What next

• Antminer S23 – the new generation with 9.5 J/TH, if you want a machine that keeps earning longer.
• ASIC miner profitability – a live table with revenue and payback for all S21 models in our range.
• How to choose an ASIC miner – how to calculate which machine pays off at your electricity price.

Sources

• No BS Bitcoin: Bitmain unveiled the S21 series (September 2023)
• Bitcoin Magazine: Antminer S21 Pro
• ForkLog: S21 XP and S21 XP Hyd
• ForkLog: S21+ and S21+ Hyd