Bitmain Antminer S21 Hydro: Features, Price, and Performance
If you’re a Bitcoin miner, you know the race for efficiency is relentless. Enter the Bitmain Antminer S21 Hydro—a machine that’s redefining what’s possible with hydro-cooling, jaw-dropping hash rates, and energy savings. But does it live up to the hype? Let’s dive into its features, price, and performance, and see how it stacks up against giants like the Antminer S19 XP Hyd and S19k Pro.
Why the S21 Hydro Is Making Waves
The Bitmain Antminer S21 Hyd 335T isn’t just another ASIC miner. It’s a leap forward, blending brute-force power with refined engineering. Here’s what sets it apart:
1. Hydro-Cooling: Silence Meets Efficiency
Traditional air-cooled miners sound like jet engines. The S21 Hydro swaps noisy fans for a hydro-cooling system that’s whisper-quiet (just 50 dB!) and ruthlessly efficient9. By circulating coolant through its veins, it maintains optimal temperatures even in sweltering environments (up to 45°C)13. This isn’t just about comfort—it extends hardware lifespan and stabilizes performance, a win for industrial farms and home miners brave enough to handle the setup3.
2. Hash Rate: Crushing the Competition
With a hash rate of 335 TH/s, the S21 Hydro leaves older models in the dust9. For perspective, the S19 XP Hyd maxes out at 255 TH/s11, while the S19k Pro hovers around 200 TH/s. That extra muscle translates to more Bitcoin mined daily—$18 in revenue before electricity costs, as of January 20259.
3. Energy Efficiency: Doing More with Less
At 16 J/Th, the S21 Hydro sips power compared to its predecessors. The S21+ Hydro variant cranks this to 15 J/Th, making it one of the most efficient miners ever13. To put that in context:
- S19 XP Hyd: ~25 J/Th
- S19k Pro: ~30 J/Th
That efficiency slashes electricity bills, turning marginal operations profitable overnight.
Performance Deep Dive: Profitability and Practicality
Let’s talk numbers. Using an electricity cost of $0.10/kWh:
- Daily Profit: 5.14(aftersubtracting5.14(aftersubtracting12.86 in power costs)9.
- Monthly Profit: ~$154.159.
But profitability hinges on Bitcoin’s price and network difficulty. When BTC hit $93,234 in early 2025, the S21 Hydro became a cash cow9. Pair it with low-cost energy (think solar or hydroelectric), and ROI accelerates.
Bitmain Antminer S21 Hydro vs. The Competition
How does the S21 Hydro stack up against Bitmain’s earlier models? Let’s break it down:
| Feature | S21 Hydro 335T | S19 XP Hyd | S19k Pro |
|---|---|---|---|
| Hash Rate | 335 TH/s | 255 TH/s | 200 TH/s |
| Power Consumption | 5360W | 5100W | 5500W |
| Efficiency (J/Th) | 16 | 20 | 27.5 |
| Noise Level | 50 dB | 75 dB | 80 dB |
| Cooling System | Hydro | Hydro | Air |
| Price Range | 5,382–5,382–7,415 | 4,500–4,500–6,200 | 3,800–3,800–5,000 |
Data sourced from Bitmain and industry reports91113.
The S21 Hydro dominates in raw power and efficiency, but the Antminer S19k Pro remains a budget-friendly entry point for small-scale miners. For large farms, though, the S21’s long-term savings justify the upfront cost.
Price and Availability: Is It Worth the Investment?
The Antminer S21 Hyd price ranges from 5,382to5,382to7,415, depending on the retailer and region9. While steep, consider this:
- ROI Timeline: ~12–18 months (assuming stable BTC prices).
- Warranty: Bitmain’s standard 6-month coverage for defects3.
Pre-orders for the S21+ Hydro opened in late 2024, with shipments starting in Q1 202513. If you’re eyeing this beast, act fast—demand is soaring as miners prep for Bitcoin’s next halving.
Key Considerations Before Buying
- Cooling Infrastructure: Hydro-cooling requires antifreeze/water setups. Not plug-and-play!
- Power Supply: At 5360W, you’ll need industrial-grade circuits.
- Noise: While quieter, it’s still not “living room friendly.”9.
Final Verdict: Who Should Buy the S21 Hydro?
- Industrial Miners: The efficiency and hash rate justify the cost.
- Tech-Savvy Home Miners: If you can handle cooling logistics, it’s a powerhouse.
- Eco-Conscious Miners: Lower energy use = smaller carbon footprint.
For everyone else? The S19k Pro or S19 XP Hyd offer solid performance at lower complexity.
Conclusion
The Bitmain Antminer S21 Hydro isn’t just a miner—it’s a statement. With hydro-cooling, unmatched efficiency, and future-proofed hash rates, it’s built for miners who refuse to settle. Yes, it’s pricey, but in the cutthroat world of Bitcoin mining, every terahash counts.
Ready to upgrade? Check out our S21 Hydro buyers’ guide for setup tips and pool recommendations. Happy mining!