Technical Specifications
| Hashrate | 298 TH/s |
|---|---|
| Power Consumption | 3,441 W |
| Efficiency | 11.5 J/TH |
| Algorithm | SHA-256 |
| Mineable Coins | Bitcoin , Bitcoin Cash |
| Noise Level | 75 dB(A) |
| Cooling | Air — 4 fans |
| Dimensions | 388 × 197 × 290 mm |
| Weight | 15.1 kg |
| Release | 2024-Q4 |
| Approx. Price | ~$5,800 USD |
Mining Profitability in 2026
The MicroBT Whatsminer M66S can be pointed at different algorithms and coins. Use our individual coin calculators with the hashrates listed in the table above:
Break-even tip: Enter the approximate price of this unit (~$5,800) in the hardware cost field of the calculator to see your estimated days-to-break-even based on current network conditions.
Pros & Cons
Pros
- Best efficiency of any MicroBT air-cooled ASIC (11.5 J/TH)
- 298 TH/s — highest raw hashrate in MicroBT's air-cooled lineup
- Proven MicroBT reliability at scale; immersion variant available (M66S+)
Cons
- High acquisition cost (~$5,000–$6,500)
- 3,441 W draw requires dedicated high-amperage circuit
- MicroBT firmware ecosystem smaller than Bitmain's
Frequently Asked Questions
How does the Whatsminer M66S compare to the Antminer S21 XP?
The M66S (298 TH/s at 11.5 J/TH) and S21 XP (270 TH/s at 12 J/TH) are the two leading air-cooled SHA-256 ASICs available in 2026. The M66S wins on raw hashrate and edges ahead on efficiency; the S21 XP benefits from Bitmain's wider support ecosystem and BOS+ firmware compatibility. Both are strong choices — compare current market prices and choose based on availability and support preferences.
Is the Whatsminer M66S profitable in 2026?
At electricity rates below $0.08/kWh, the M66S is one of the most profitable air-cooled Bitcoin miners available in 2026. Its 11.5 J/TH efficiency means it withstands difficulty increases and price drops better than older models. Use our Bitcoin mining calculator with 298 TH/s and 3,441 W for a real-time profitability estimate at your electricity rate.
Is there an immersion version of the M66S?
Yes — MicroBT offers the M66S+ specifically designed for liquid immersion cooling. The immersion variant can operate at higher core frequencies, improving efficiency beyond the air-cooled M66S's already strong 11.5 J/TH. If you have or are building an immersion tank infrastructure, the M66S+ offers a meaningful performance step up over the standard unit.
What is the M66S upgrade path from older MicroBT models?
The M66S is the direct successor to the M60S (186 TH/s at 18.5 J/TH). The hashrate improvement is 60% and efficiency improves by ~38%. If you operate M60S units, replacing them with M66S hardware significantly improves your profitability at the same electrical infrastructure. The physical form factor is similar, making rack-replacement straightforward in existing facilities.
Where to Buy
The MicroBT Whatsminer M66S is available from:
- MicroBT Official — microbt.com
- Compass Mining — US-based, with hosting options
- eBay / secondary market — used units, verify hashrate stability before purchasing
Price estimates on this page are approximate and subject to market fluctuations. Always compare prices from multiple sellers before purchasing.
Compare the MicroBT Whatsminer M66S
See how the MicroBT Whatsminer M66S stacks up against other miners that can mine the same coins — hashrate, power draw, efficiency, and profitability side by side: