MicroBT Whatsminer M21S vs MicroBT Whatsminer M66
Side-by-side specs, profitability, and home mining comparison.
Specifications Comparison
| MicroBT Whatsminer M21S | Specification | MicroBT Whatsminer M66 |
|---|---|---|
| 56.0 TH/s | Hashrate | 238.0 TH/s |
| 3,360 W | Power Consumption | 4,736 W |
| 60.0 J/TH | Efficiency | 19.9 J/TH |
| — | Noise Level | — |
| 12,500.0 kg | Weight | 16.0 kg |
| 11,464 BTU/hr | BTU Output | 16,159 BTU/hr |
| 22/100 | Home Mining Score | 16/100 |
| — | Release Year | — |
| SHA-256 | Algorithm | SHA-256 |
| MicroBT | Manufacturer | MicroBT |
Profitability Comparison
MicroBT Whatsminer M21S
MicroBT Whatsminer M66
Based on BTC price of $76,751 and current network difficulty as of May 18, 2026. Actual results vary.
Verdict
Based on our multi-factor analysis, the MicroBT Whatsminer M66 wins on 2 of 5 factors (efficiency, hashrate). The standout gap is 325% more hashrate (56.0 vs 238.0 TH/s) in the MicroBT Whatsminer M66's favour. The MicroBT Whatsminer M21S claws back ground on power consumption and home mining score and price-performance. Cross-check the spec deltas and operating-cost table above against your own electricity rate before deciding.
Spec Deltas
Stripped to the numbers, this is how far apart the MicroBT Whatsminer M21S and MicroBT Whatsminer M66 sit on each measurable spec:
- MicroBT Whatsminer M66 325% more hashrate (56.0 vs 238.0 TH/s)
- MicroBT Whatsminer M21S 29% better power draw (3,360 vs 4,736 W)
- MicroBT Whatsminer M66 67% better efficiency (60.0 vs 19.9 J/TH)
- MicroBT Whatsminer M66 100% better weight (12,500.0 vs 16.0 kg)
- MicroBT Whatsminer M66 41% more heat output (11,464 vs 16,159 BTU/hr)
- MicroBT Whatsminer M21S 38% more home mining score (22.0 vs 16.0)
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.
| MicroBT Whatsminer M21S | Metric | MicroBT Whatsminer M66 |
|---|---|---|
| $650 | Upfront cost (MSRP) | $3,672 |
| -$6.09 | Daily net profit | -$2.96 |
| -$2,871 | Net after 1 year | -$4,753 |
| -$5,093 | Net after 2 years | -$5,833 |
| -$7,314 | Net after 3 years | -$6,914 |
| Does not pay back at current rates (negative daily profit) | 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
MicroBT Whatsminer M21SScore: 22/100. 0 dB noise level.
Best for Efficiency
MicroBT Whatsminer M6619.9 J/TH — lower electricity cost per terahash.
Frequently Asked Questions
Which makes more money, the MicroBT Whatsminer M21S or the MicroBT Whatsminer M66?
At the current BTC price and a $0.10/kWh electricity rate, the MicroBT Whatsminer M66 is more profitable at $-2.96/day compared to $-6.09/day for the MicroBT Whatsminer M21S. Profitability depends heavily on your electricity rate — use the selector above to calculate with your actual costs.
Is the MicroBT Whatsminer M21S or the MicroBT Whatsminer M66 better for noise-sensitive spaces?
Both miners have similar noise levels. Check the specs table above for exact decibel readings.
MicroBT Whatsminer M21S vs MicroBT Whatsminer M66: which fits a residential setup better?
The MicroBT Whatsminer M21S scores 22/100 on our Home Mining Score (vs 16/100 for the MicroBT Whatsminer M66). 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 M21S and MicroBT Whatsminer M66 on J/TH?
The MicroBT Whatsminer M21S runs at 60.0 J/TH while the MicroBT Whatsminer M66 runs at 19.9 J/TH — a difference of 40.1 J/TH. Lower efficiency means less electricity per terahash of mining power, directly reducing operating costs. In relative terms that is 67% better efficiency (60.0 vs 19.9 J/TH).