Technical Specifications
| Hashrate | 200 TH/s |
|---|---|
| Power Consumption | 3,500 W |
| Efficiency | 17.5 J/TH |
| Algorithm | SHA-256 |
| Mineable Coins | Bitcoin , Bitcoin Cash |
| Noise Level | 75 dB(A) |
| Cooling | Air — 4 fans |
| Dimensions | 400 × 195 × 290 mm |
| Weight | 13.5 kg |
| Release | 2024-Q1 |
| Approx. Price | ~$3,200 USD |
Mining Profitability in 2026
The Bitmain Antminer S21 can be pointed at different algorithms and coins. Use our individual coin calculators with the hashrates listed in the table above:
Break-even tip: Enter the approximate price of this unit (~$3,200) in the hardware cost field of the calculator to see your estimated days-to-break-even based on current network conditions.
Pros & Cons
Pros
- 200 TH/s — strong absolute hashrate for Bitcoin mining
- Lower acquisition cost than the S21 Pro (~$3,000–3,500)
- Same chassis and power infrastructure as S21 Pro
Cons
- Less efficient than S21 Pro (17.5 vs 15 J/TH)
- 3,500 W power draw still requires industrial setup
- Noise level identical to Pro (75 dB)
Frequently Asked Questions
What is the difference between the Antminer S21 and S21 Pro?
The S21 Pro delivers 234 TH/s at 15 J/TH versus the standard S21's 200 TH/s at 17.5 J/TH. The Pro is ~17% more efficient per unit of hashrate and earns more per watt — justifying its ~40% price premium for operators running long-term at scale. The standard S21 suits miners who prefer lower upfront cost and are comfortable with slightly thinner margins.
Is the Antminer S21 still worth buying in 2026?
At electricity rates below $0.08/kWh, the S21 can still generate positive returns in 2026, particularly if purchased at a competitive secondary-market price. Its 17.5 J/TH efficiency is materially better than older S19 models. Compare it against the S21 Pro and Whatsminer M60S to determine which offers the best ROI at your specific electricity rate and target coin.
What firmware options are available for the Antminer S21?
The S21 supports Bitmain's stock firmware with auto-tune and overclock modes. Third-party firmware BOS+ (Braiins OS+) supports the S21 and typically unlocks 5–15% efficiency improvements through per-chip autotuning. BOS+ charges a 2% mining reward dev fee, which is generally recouped within days via efficiency gains at scale.
How do I configure the Antminer S21 for a mining pool?
Connect to 220 V power and Ethernet. Access the web interface at the unit's IP address (find it via your router's DHCP lease list). Navigate to Miner Configuration, enter your pool URL (e.g. stratum+tcp://btc.f2pool.com:3333), worker name (your wallet address or pool username dot worker label), and password (usually x). The unit begins hashing within 2–3 minutes.
Where to Buy
The Bitmain Antminer S21 is available from:
- Bitmain Official Shop — shop.bitmain.com (new units, with warranty)
- MinerBros — authorised reseller, ships globally
- Kaboomracks — US-based reseller, new and refurbished
- eBay / secondary market — used units, verify hashrate stability before purchasing
Price estimates on this page are approximate and subject to market fluctuations. Always compare prices from multiple sellers before purchasing.
Compare the Bitmain Antminer S21
See how the Bitmain Antminer S21 stacks up against other miners that can mine the same coins — hashrate, power draw, efficiency, and profitability side by side: