MicroBT Whatsminer M21 vs Whatsminer M66S
Side-by-side specs, profitability, and home mining comparison.
Specifications Comparison
| MicroBT Whatsminer M21 | Specification | Whatsminer M66S |
|---|---|---|
| 31.0 TH/s | Hashrate | 298.0 TH/s |
| 1,860 W | Power Consumption | 5,518 W |
| 60.0 J/TH | Efficiency | 18.5 J/TH |
| — | Noise Level | 50 dB |
| 7,150.0 kg | Weight | 13.5 kg |
| 6,346 BTU/hr | BTU Output | 18,827 BTU/hr |
| 28/100 | Home Mining Score | 44/100 |
| — | Release Year | — |
| SHA-256 | Algorithm | SHA-256 |
| MicroBT | Manufacturer | MicroBT |
Profitability Comparison
MicroBT Whatsminer M21
Whatsminer M66S
Based on BTC price of $78,170 and current network difficulty as of May 16, 2026. Actual results vary.
Verdict
Our scoring model gives the nod to the Whatsminer M66S, which leads on 4 of 5 weighted factors (efficiency, hashrate, home mining score, noise level). Its biggest concrete edge: 861% more hashrate (31.0 vs 298.0 TH/s). The MicroBT Whatsminer M21 claws back ground on power consumption. The right pick still depends on your power cost and noise tolerance — the breakdowns above make that call concrete.
Spec Deltas
Stripped to the numbers, this is how far apart the MicroBT Whatsminer M21 and Whatsminer M66S sit on each measurable spec:
- Whatsminer M66S 861% more hashrate (31.0 vs 298.0 TH/s)
- MicroBT Whatsminer M21 66% better power draw (1,860 vs 5,518 W)
- Whatsminer M66S 69% better efficiency (60.0 vs 18.5 J/TH)
- Whatsminer M66S 100% better weight (7,150.0 vs 13.5 kg)
- Whatsminer M66S 197% more heat output (6,346 vs 18,827 BTU/hr)
- Whatsminer M66S 57% more home mining score (28.0 vs 44.0)
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.
| MicroBT Whatsminer M21 | Metric | Whatsminer M66S |
|---|---|---|
| — | Upfront cost (MSRP) | $8,000 |
| -$3.35 | Daily net profit | -$2.52 |
| -$1,222 | Net after 1 year | -$8,921 |
| -$2,445 | Net after 2 years | -$9,842 |
| -$3,667 | Net after 3 years | -$10,763 |
| — | 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
TieBoth miners produce similar daily profit.
Best for Home Mining
Whatsminer M66SScore: 44/100. 50 dB noise level.
Best for Efficiency
Whatsminer M66S18.5 J/TH — lower electricity cost per terahash.
Frequently Asked Questions
Is the MicroBT Whatsminer M21 or Whatsminer M66S more profitable?
At the current BTC price and a $0.10/kWh electricity rate, the Whatsminer M66S is more profitable at $-2.52/day compared to $-3.35/day for the MicroBT Whatsminer M21. Profitability depends heavily on your electricity rate — use the selector above to calculate with your actual costs.
Is the MicroBT Whatsminer M21 or the Whatsminer M66S better for noise-sensitive spaces?
The Whatsminer M66S is quieter at 50 dB compared to the MicroBT Whatsminer M21 at 0 dB. For home mining, lower noise levels make a significant difference in livability.
Which is better for home mining, the MicroBT Whatsminer M21 or Whatsminer M66S?
The Whatsminer M66S scores 44/100 on our Home Mining Score (vs 28/100 for the MicroBT Whatsminer M21). This composite score factors in noise, power requirements, heat output, size, and setup ease — all critical for residential mining.
How far apart are the MicroBT Whatsminer M21 and Whatsminer M66S on J/TH?
The MicroBT Whatsminer M21 runs at 60.0 J/TH while the Whatsminer M66S runs at 18.5 J/TH — a difference of 41.5 J/TH. Lower efficiency means less electricity per terahash of mining power, directly reducing operating costs. In relative terms that is 69% better efficiency (60.0 vs 18.5 J/TH).