Antminer S21+ vs Bitmain Antminer S9 Hydro (18Th)
Side-by-side specs, profitability, and home mining comparison.
Specifications Comparison
| Antminer S21+ | Specification | Bitmain Antminer S9 Hydro (18Th) |
|---|---|---|
| 216.0 TH/s | Taux de hachage | 18.0 TH/s |
| 3,564 W | Consommation électrique | 1,728 W |
| 16.5 J/TH | Efficiency | 96.0 J/TH |
| 75 dB | Niveau de bruit | — |
| 15.0 kg | Weight | 5,150.0 kg |
| 12,160 BTU/hr | BTU Output | 5,896 BTU/hr |
| 30/100 | Home Mining Score | 28/100 |
| — | Release Year | — |
| SHA-256 | Algorithme | SHA-256 |
| Bitmain | Manufacturer | Bitmain |
Profitability Comparison
Antminer S21+
Bitmain Antminer S9 Hydro (18Th)
Based on BTC price of $78,179 and current network difficulty as of May 17, 2026. Actual results vary.
Verdict
Our scoring model gives the nod to the Antminer S21+, which leads on 4 of 5 weighted factors (efficacité, hashrate, score de minage domestique, niveau sonore). The standout gap is 1100% more hashrate (216.0 vs 18.0 TH/s) in the Antminer S21+'s favour. The Bitmain Antminer S9 Hydro (18Th) claws back ground on consommation électrique. The right pick still depends on your power cost and noise tolerance — the breakdowns above make that call concrete.
Spec Deltas
The Antminer S21+ and Bitmain Antminer S9 Hydro (18Th) diverge on the metrics below — each gap expressed as a real percentage, not a vague "better":
- Antminer S21+ 1100% more hashrate (216.0 vs 18.0 TH/s)
- Bitmain Antminer S9 Hydro (18Th) 52% better power draw (3,564 vs 1,728 W)
- Antminer S21+ 83% better efficacité (16.5 vs 96.0 J/TH)
- Antminer S21+ 100% better weight (15.0 vs 5,150.0 kg)
- Antminer S21+ 106% more heat output (12,160 vs 5,896 BTU/hr)
- Antminer S21+ 7% more score de minage domestique (30.0 vs 28.0)
Cost & ROI Over Time
A miner pays for itself in profit, not specs. These projections track upfront cost against one, two and three years of net earnings at $0.10/kWh.
| Antminer S21+ | Metric | Bitmain Antminer S9 Hydro (18Th) |
|---|---|---|
| $6,500 | Upfront cost (MSRP) | — |
| -$0.78 | Daily net profit | -$3.50 |
| -$6,786 | Net after 1 year | -$1,277 |
| -$7,071 | Net after 2 years | -$2,555 |
| -$7,357 | Net after 3 years | -$3,832 |
| 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 S21+Score: 30/100. 75 dB noise level.
Best for Efficiency
Antminer S21+16.5 J/TH — lower electricity cost per terahash.
Frequently Asked Questions
Antminer S21+ vs Bitmain Antminer S9 Hydro (18Th): which one earns more per day?
At the current BTC price and a $0.10/kWh electricity rate, the Antminer S21+ is more profitable at $-0.78/day compared to $-3.50/day for the Bitmain Antminer S9 Hydro (18Th). Profitability depends heavily on your electricity rate — use the selector above to calculate with your actual costs.
Is the Antminer S21+ or the Bitmain Antminer S9 Hydro (18Th) better for noise-sensitive spaces?
The Antminer S21+ is quieter at 75 dB compared to the Bitmain Antminer S9 Hydro (18Th) at 0 dB. For home mining, lower noise levels make a significant difference in livability.
Antminer S21+ vs Bitmain Antminer S9 Hydro (18Th): which fits a residential setup better?
The Antminer S21+ scores 30/100 on our Home Mining Score (vs 28/100 for the Bitmain Antminer S9 Hydro (18Th)). This composite score factors in noise, power requirements, heat output, size, and setup ease — all critical for residential mining.
Antminer S21+ vs Bitmain Antminer S9 Hydro (18Th): how much does the efficiency gap matter?
The Antminer S21+ runs at 16.5 J/TH while the Bitmain Antminer S9 Hydro (18Th) runs at 96.0 J/TH — a difference of 79.5 J/TH. Lower efficiency means less electricity per terahash of mining power, directly reducing operating costs. In relative terms that is 83% better efficacité (16.5 vs 96.0 J/TH).