Antminer S21+ Hyd (used)

Antminer S21+ Hyd

395 TH/s / In stock Hong Kong / At home
73 199 Kč
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Antminer S21+ Hyd (used)
  • Antminer S21+ Hyd (used)
Antminer S21+ Hyd

Bitmain · SHA-256

Antminer S21+ Hyd

Mines approx. 309 Kč per day ≈ 9267 Kč / month
0.000177 BTC / day · before electricity costs · exchange rate and network difficulty as of 25 Oct, 11:59 Calculate profit after electricity
On our hosting (electricity from 1.14 Kč/kWh): ≈ 147 Kč a day after electricity, payback 13 months
60 495 Kč excl. VAT
73 199 Kč incl. 21% VAT
Hashrate
Where will the miner run
Delivery
Hashrate
Delivery
Operation

What it can mine

Gross revenue before electricity, based on today’s difficulty and exchange rate. Coins without an amount are not calculated yet.

Suitable for

  • Hosting
  • Workshop – with a water loop
  • Flat – needs a cooling loop
Full description, video and specifications
395 TH/sHashrate – mining power
5925 WPower draw at the wall
15.0 J/THEfficiency – lower is better
HydroCooling
50 dBNoise level – like a quiet office
Rows of ASIC miners in a data centre Current hosting prices · 22/10/2026
PC Praha hosting

Let it mine with us

The miner goes from the supplier straight to the data centre. We connect it and look after it; you just follow the earnings.

  • from 1.14 Kč/kWhelectricity incl. management · with prepayment up to −30%
  • 7-year warrantywhile the miner runs with us (at home 2 years)
  • 7 data centresto choose from, uptime up to 99.85%
  • 0 dB at home50 dB of noise stays in the data centre

Technical specifications

Manufacturer
Bitmain
Algorithm
SHA-256
Coins
Bitcoin, Bitcoin Cash, Bitcoin SV, DigiByte, eCash, Fractal Bitcoin, Quai
Hashrate
395 TH/s
Power draw
5925 W
Efficiency
15.0 J/TH
Cooling
Hydro
Noise level
50 dB
Power supply
380–415 V, 3-phase
Condition
New
Warranty
24 months · 84 months when hosted with us

How much it earns

Enter your tariff. The default value is an example.

Revenue per day
Electricity per day
Profit per day

Revenue based on the current network difficulty and exchange rate, updated 25/10/2026 11:59. We use today’s revenue. In reality it changes with network difficulty, the exchange rate and halvings, so treat multi-year figures as indicative. Pool fees are not included.

  • Personal collectionPrague 10
  • ASIC miner repairsright here in Prague
  • Pay by bank transfer or in cryptoBank transfer (CZK / €), USDT/USDC or cash at the shop
  • VAT invoicereverse charge for EU businesses

Description

The Antminer S21+ Hyd is a water-cooled SHA-256 miner from Bitmain for mining Bitcoin. It is made in 319, 358 and 395 TH/s versions; the most powerful version draws roughly 5,925 W, i.e. around 15 J/TH (319 and 358 TH/s around 16 J/TH). Thanks to liquid cooling it is much quieter than air-cooled machines.

The model is available in 319, 358 and 395 TH/s versions – choose the hashrate above, next to the price.

Key features

  • 319–395 TH/s on SHA-256 – high hashrate in a single machine.
  • Water cooling – noise around 50 dB; the heat goes into the liquid and can be reused.
  • Three-phase power supply 380–415 V.
  • Compact fanless body, suitable for a rack.

Who it is for

For miners with a water loop and a dry cooler, for industrial operations, or for those who place the machine in our hosting. Without water infrastructure you cannot run it at home.

Operation and installation

The miner needs a closed water loop with a pump and a cooler sized for just under 6 kW of heat (depending on the chosen hashrate), a quality coolant and a three-phase connection. The heat can be used for space heating or hot water. Connection via Ethernet.

Use the calculator below to see how much it earns at the current exchange rate and electricity price.

Frequently asked questions

What are the Antminer S21+ Hyd specifications?
SHA-256 algorithm, hashrate 319, 358 or 395 TH/s (choose the hashrate next to the price), power draw around 5,925 W for 395 TH/s, efficiency 15–16 J/TH, water cooling, power supply 380–415 V (3-phase), noise around 50 dB.
What do I need to run it?
A water loop with a pump and a dry cooler for just under 6 kW of heat, coolant and a three-phase connection. If you have none of these, our hosting is the simplest option.
Can I run the machine on your hosting?
Yes. When ordering, choose “Hosted” – the machine goes from the supplier straight to our data centre, and you get it at a discounted price. You pay for electricity separately depending on the location; you can see the prices of the individual data centres in the calculator on this page. The machine remains yours.
How much will the machine earn?
The calculator on this page estimates the daily earnings based on the current network difficulty, the exchange rate and your electricity price. Earnings change with difficulty, coin price and uptime, so treat them as an estimate, not a promise.
Can the heat be reused?
Yes, that is the advantage of water cooling – the heat from the coolant can be used via a heat exchanger for space heating or hot water.
How loud is a hydro miner?
The hydro miner itself is quiet thanks to water cooling; the noise comes mainly from the cooler that removes heat from the water. The fan radiator we offer runs at roughly 55–65 dB. The resulting noise level depends on how you dissipate the heat – if you use it for heating, for example, the cooler fans will hardly run in winter and will work harder in summer.

Setup guide

We will set it up for you free of charge. Send us your wallet address and the miner will mine for you alone. If you do not have a wallet yet, we will help you create one.

Setting up an Antminer (Bitmain) miner
  1. Connect the network first, then the power. Connect the miner to your router with a network cable, on the same network as your computer. Only then switch it on.
  2. Find the IP address. Download the official Bitmain IP Reporter, run it and press the IP Report button on the miner – the address will appear in the program. You can also find it in your router’s list of devices.
  3. Log in. Enter the IP address in your browser and log in with the default username and password root / root. Then change the password.
  4. Set up the pool. In the pool settings (Miner Configuration), enter the pool address in the form stratum+tcp://…; as the Worker, enter your pool account name or wallet address, a full stop and the machine name (e.g. account.miner1), and x as the password. Save.
  5. Check that it is mining. After a few minutes the miner will start mining. You can check the hashrate on the pool’s website.

Switch on Hyd (water-cooled) and Imm (immersion) models only after connecting them to the cooling circuit.

Nastavení poolu v ovládacím panelu Antmineru

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