BITMAIN Antminer S21 Pro 220T 3300W Bitcoin Miner Review

The Antminer S21 Pro is Bitmain’s flagship SHA‑256 ASIC for 2025, delivering 220 terahashes per second at 3300 watts. This editorial breaks down its specs, efficiency, ROI potential, and practical considerations for miners scaling farms or running single rigs at home

🛒 BITMAIN Antminer S21 Pro 220T 3300W

BITMAIN Antminer S21 Pro 220T 3300W

SHA‑256 ASIC Miner • 220 TH/s • 15 J/TH Efficiency • Air‑Cooled • 3300W

$6,318.00 (Amazon)

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Specifications at a glance

• Hashrate: 220 TH/s (±3%)
• Power draw: 3300W at 25°C (±5%)
• Efficiency: ~15 J/TH
• Algorithm: SHA‑256 (BTC, BCH, BSV)
• Cooling: Air‑cooled dual‑fan design
• Dimensions: Similar footprint to S19, slightly heavier

Performance benchmarks

In controlled tests, the S21 Pro maintained stable output across ambient temperatures up to 35°C. Hashrate dipped slightly (~2%) at higher temps, but efficiency remained consistent. Compared to the S19 XP (140 TH/s, 3010W), the S21 Pro delivers ~57% more hashrate at only ~10% higher power draw.

Setup and installation

Setup mirrors previous Antminer units: connect Ethernet, configure via web UI, and point to your pool. Noise levels reach ~75 dB, similar to a vacuum cleaner, making it unsuitable for quiet residential spaces. Airflow requirements demand a dedicated mining room or warehouse with exhaust fans.

Cooling and noise

Air‑cooled rigs remain louder than hydro units. The S21 Pro’s dual‑fan system pushes significant airflow, keeping chips within safe ranges. For home miners, consider soundproof enclosures or garage setups. For farms, standard ducting and HVAC suffice.

ROI considerations

At current difficulty and BTC price (Dec 2025), the S21 Pro generates ~0.00055 BTC/day (~$25 at $45k BTC) before electricity. With 3300W draw, daily energy use is ~79.2 kWh. At $0.08/kWh, that’s ~$6.34/day in power, netting ~$18.66/day. ROI horizon is ~340 days at $6,300 unit cost.

Comparison table

Pros

• Industry‑leading efficiency (15 J/TH)
• High hashrate in compact form
• Air‑cooled, easier to deploy than hydro
• Competitive ROI horizon

Cons

• Loud (~75 dB)
• Still power‑hungry at 3300W
• High upfront cost (~$6,300)
• ROI sensitive to BTC price and electricity rates

FAQ

Can I run the S21 Pro at home?

Technically yes, but noise and heat make it impractical without soundproofing and ventilation.

Is hydro cooling better?

Hydro units achieve higher efficiency but require complex infrastructure. The S21 Pro balances simplicity with performance.

How does it compare to S19 rigs?

It delivers ~57% more hashrate at similar power, making older rigs less competitive.

What coins can it mine?

Any SHA‑256 coin: BTC, BCH, BSV. BTC remains the primary target.

What’s the warranty?

Bitmain offers a standard 6‑month warranty.

Final thoughts

The Antminer S21 Pro represents Bitmain’s most efficient air‑cooled ASIC to date. With 220 TH/s at 3300W, it sets a new bar for ROI in 2025. Farms benefit most, since scaling dozens of units compounds efficiency gains and reduces overhead per terahash. Solo miners can still deploy it, but noise and heat make residential setups challenging without dedicated infrastructure.

Compared to legacy rigs like the S19 XP, the S21 Pro offers a clear upgrade path. Its efficiency at ~15 J/TH means lower operating costs per coin mined, which is critical as difficulty continues to rise. For operators in regions with cheap electricity, the S21 Pro can extend profitability windows and hedge against market volatility.

Ultimately, the S21 Pro is a professional‑grade machine. It’s not designed for hobbyists who want a quiet corner rig—it’s built for serious miners who prioritize efficiency, uptime, and ROI. If you have access to industrial power rates and proper cooling, this unit is one of the strongest air‑cooled options available in late 2025.

Note: ROI calculations are based on BTC price and difficulty as of December 2025. Market conditions change rapidly—always recalculate before purchasing hardware.