Antminer S21 Hydro vs Antminer S9j
Side-by-side specs, profitability, and home mining comparison.
Specifications Comparison
| Antminer S21 Hydro | Specification | Antminer S9j |
|---|---|---|
| 335.0 TH/s | Taux de hachage | 14.5 TH/s |
| 5,360 W | Consommation électrique | 1,350 W |
| 16.0 J/TH | Efficiency | 93.1 J/TH |
| 50 dB | Niveau de bruit | 76 dB |
| 15.8 kg | Weight | 4.2 kg |
| 18,288 BTU/hr | BTU Output | 4,606 BTU/hr |
| 44/100 | Home Mining Score | 83/100 |
| — | Release Year | — |
| SHA-256 | Algorithme | SHA-256 |
| Bitmain | Manufacturer | Bitmain |
Profitability Comparison
Antminer S21 Hydro
Antminer S9j
Based on BTC price of $78,128 and current network difficulty as of May 17, 2026. Actual results vary.
Verdict
Our scoring model gives the nod to the Antminer S21 Hydro, which leads on 3 of 5 weighted factors (efficacité, hashrate, niveau sonore). The standout gap is 2210% more hashrate (335.0 vs 14.5 TH/s) in the Antminer S21 Hydro's favour. That said, the Antminer S9j isn't beaten everywhere — it still wins consommation électrique and score de minage domestique. Review the detailed specs and profitability calculations above to determine which miner best fits your specific setup.
Spec Deltas
Stripped to the numbers, this is how far apart the Antminer S21 Hydro and Antminer S9j sit on each measurable spec:
- Antminer S21 Hydro 2210% more hashrate (335.0 vs 14.5 TH/s)
- Antminer S9j 75% better power draw (5,360 vs 1,350 W)
- Antminer S21 Hydro 83% better efficacité (16.0 vs 93.1 J/TH)
- Antminer S21 Hydro 34% better noise (50.0 vs 76.0 dB)
- Antminer S9j 73% better weight (15.8 vs 4.2 kg)
- Antminer S21 Hydro 297% more heat output (18,288 vs 4,606 BTU/hr)
- Antminer S9j 89% more score de minage domestique (44.0 vs 83.0)
Cost & ROI Over Time
Sticker price versus what the miner actually earns back: the table below projects cumulative net profit at a $0.10/kWh electricity rate.
| Antminer S21 Hydro | Metric | Antminer S9j |
|---|---|---|
| $9,500 | Upfront cost (MSRP) | — |
| -$0.82 | Daily net profit | -$2.72 |
| -$9,799 | Net after 1 year | -$992 |
| -$10,098 | Net after 2 years | -$1,985 |
| -$10,398 | Net after 3 years | -$2,977 |
| Does not pay back at current rates (negative daily profit) | Payback period | — |
Projections assume continuous operation, a flat $0.10/kWh rate, and no hardware degradation, pool fees, or BTC price change. Real-world ROI varies.
Best For...
Best for Profitability
TieBoth miners produce similar daily profit.
Best for Home Mining
Antminer S9jScore: 83/100. 76 dB noise level.
Best for Efficiency
Antminer S21 Hydro16.0 J/TH — lower electricity cost per terahash.
Frequently Asked Questions
Antminer S21 Hydro vs Antminer S9j: which one earns more per day?
At the current BTC price and a $0.10/kWh electricity rate, the Antminer S21 Hydro is more profitable at $-0.82/day compared to $-2.72/day for the Antminer S9j. Profitability depends heavily on your electricity rate — use the selector above to calculate with your actual costs.
Antminer S21 Hydro vs Antminer S9j: which runs at a lower noise level?
The Antminer S21 Hydro is quieter at 50 dB compared to the Antminer S9j at 76 dB. For home mining, lower noise levels make a significant difference in livability.
Which is better for home mining, the Antminer S21 Hydro or Antminer S9j?
The Antminer S9j scores 83/100 on our Home Mining Score (vs 44/100 for the Antminer S21 Hydro). This composite score factors in noise, power requirements, heat output, size, and setup ease — all critical for residential mining.
Antminer S21 Hydro vs Antminer S9j: how much does the efficiency gap matter?
The Antminer S21 Hydro runs at 16.0 J/TH while the Antminer S9j runs at 93.1 J/TH — a difference of 77.1 J/TH. Lower efficiency means less electricity per terahash of mining power, directly reducing operating costs. In relative terms that is 83% better efficacité (16.0 vs 93.1 J/TH).