Bitmain Antminer S21 XP Immersion vs Whatsminer M66S
Side-by-side specs, profitability, and home mining comparison.
Specifications Comparison
| Bitmain Antminer S21 XP Immersion | Specification | Whatsminer M66S |
|---|---|---|
| 300.0 TH/s | Taux de hachage | 298.0 TH/s |
| 4,050 W | Consommation électrique | 5,518 W |
| 13.5 J/TH | Efficiency | 18.5 J/TH |
| 50 dB | Niveau de bruit | 50 dB |
| 14.4 kg | Weight | 13.5 kg |
| 13,819 BTU/hr | BTU Output | 18,827 BTU/hr |
| 44/100 | Home Mining Score | 44/100 |
| — | Release Year | — |
| SHA-256 | Algorithme | SHA-256 |
| Bitmain | Manufacturer | MicroBT |
Profitability Comparison
Bitmain Antminer S21 XP Immersion
Whatsminer M66S
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 Bitmain Antminer S21 XP Immersion, which leads on 4 of 4 weighted factors (efficacité, hashrate, consommation électrique, rapport qualité-prix). The standout gap is 27% better efficacité (13.5 vs 18.5 J/TH) in the Bitmain Antminer S21 XP Immersion's favour. 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 Bitmain Antminer S21 XP Immersion and Whatsminer M66S sit on each measurable spec:
- Bitmain Antminer S21 XP Immersion 1% more hashrate (300 vs 298 TH/s)
- Bitmain Antminer S21 XP Immersion 27% better power draw (4,050 vs 5,518 W)
- Bitmain Antminer S21 XP Immersion 27% better efficacité (13.5 vs 18.5 J/TH)
- Whatsminer M66S 6% better weight (14.4 vs 13.5 kg)
- Whatsminer M66S 36% more heat output (13,819 vs 18,827 BTU/hr)
Cost & ROI Over Time
Hardware cost is only half the story — here is how each miner's upfront price plays out against cumulative profit at a $0.10/kWh rate.
| Bitmain Antminer S21 XP Immersion | Metric | Whatsminer M66S |
|---|---|---|
| $1,593 | Upfront cost (MSRP) | $8,000 |
| $1.07 | Daily net profit | -$2.52 |
| -$1,201 | Net after 1 year | -$8,921 |
| -$810 | Net after 2 years | -$9,841 |
| -$418 | Net after 3 years | -$10,762 |
| Takes ~4.1 years to pay back at current rates | Payback period | Does not pay back at current rates (negative daily profit) |
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
Bitmain Antminer S21 XP Immersion$3.60/day higher profit at current rates.
Best for Home Mining
TieBoth miners are equally suitable for home use.
Best for Efficiency
Bitmain Antminer S21 XP Immersion13.5 J/TH — lower electricity cost per terahash.
Frequently Asked Questions
Which makes more money, the Bitmain Antminer S21 XP Immersion or the Whatsminer M66S?
At the current BTC price and a $0.10/kWh electricity rate, the Bitmain Antminer S21 XP Immersion is more profitable at $1.07/day compared to $-2.52/day for the Whatsminer M66S. Profitability depends heavily on your electricity rate — use the selector above to calculate with your actual costs.
Bitmain Antminer S21 XP Immersion vs Whatsminer M66S: which runs at a lower noise level?
Both miners have similar noise levels. Check the specs table above for exact decibel readings.
Which is better for home mining, the Bitmain Antminer S21 XP Immersion or Whatsminer M66S?
Both miners score similarly on our Home Mining Score. Consider your specific constraints (noise tolerance, available power, heat needs) to decide.
Bitmain Antminer S21 XP Immersion vs Whatsminer M66S: how much does the efficiency gap matter?
The Bitmain Antminer S21 XP Immersion runs at 13.5 J/TH while the Whatsminer M66S runs at 18.5 J/TH — a difference of 5.0 J/TH. Lower efficiency means less electricity per terahash of mining power, directly reducing operating costs. In relative terms that is 27% better efficacité (13.5 vs 18.5 J/TH).