Bitmain Antminer S21 XP vs MicroBT Whatsminer M66S

Mining profitability comparison for Bitcoin (BTC), Bitcoin Cash (BCH)

★ MicroBT Whatsminer M66S is more efficient for Bitcoin mining

Verdict: Bitmain Antminer S21 XP vs MicroBT Whatsminer M66S

For Bitcoin mining, the MicroBT Whatsminer M66S is the more efficient choice, delivering roughly 4% more hashrate per watt than the Bitmain Antminer S21 XP. The Bitmain Antminer S21 XP draws 196W less, cutting electricity costs by about $120/year at $0.07/kWh. Bottom line: if power efficiency is your priority, the MicroBT Whatsminer M66S is the stronger pick — but confirm with your real electricity rate and current hardware prices below, since acquisition cost ultimately drives ROI.

Specifications

Spec Bitmain Antminer S21 XP MicroBT Whatsminer M66S
Type ASIC ASIC
Algorithm
Hashrate (BTC) 270 TH/s 298 TH/s
Power Draw 3245 W 3441 W
Efficiency 12 J/TH 11.5 J/TH
Supported Coins BTC, BCH BTC, BCH
Release Year N/A N/A

Hashrate & Efficiency per Coin

Coin Bitmain XP HR MicroBT M66S HR Power A Power B More Efficient
BTC 270 TH/s 298 TH/s 3245 W 3441 W Whatsminer ✓
BCH 270 TH/s 298 TH/s 3245 W 3441 W Whatsminer ✓

Daily Electricity Cost at Different Rates

Electricity cost only (not including coin revenue). Lower is better for any given rate.

Electricity Rate Bitmain Antminer S21 XP MicroBT Whatsminer M66S Difference
$0.04/kWh $3.12 $3.30 -$0.19 (A cheaper)
$0.06/kWh $4.67 $4.96 -$0.28 (A cheaper)
$0.07/kWh $5.45 $5.78 -$0.33 (A cheaper)
$0.1/kWh $7.79 $8.26 -$0.47 (A cheaper)
$0.12/kWh $9.35 $9.91 -$0.56 (A cheaper)
$0.15/kWh $11.68 $12.39 -$0.71 (A cheaper)
$0.2/kWh $15.58 $16.52 -$0.94 (A cheaper)

Pros & Cons

Bitmain Antminer S21 XP

  • Best efficiency among air-cooled SHA-256 ASICs (12 J/TH)
  • 270 TH/s — highest hashrate in the S21 air-cooled lineup
  • Standard air-cooled form factor: no special infrastructure needed beyond dedicated power
  • Highest acquisition cost in the S21 air-cooled range (~$6,000–$7,500)
  • 3,245 W still requires a dedicated 16 A / 220 V circuit
  • Price premium over S21 Pro narrows at lower BTC prices

MicroBT Whatsminer M66S

  • 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+)
  • 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

Is the Bitmain Antminer S21 XP or MicroBT Whatsminer M66S more profitable for Bitcoin mining?

Based on hashrate-per-watt efficiency, the MicroBT Whatsminer M66S is more efficient for Bitcoin mining. However, actual profitability depends on your electricity cost, hardware acquisition price, and coin price — use the live calculator for exact numbers.

What is the power consumption difference between the Bitmain Antminer S21 XP and MicroBT Whatsminer M66S?

For Bitcoin mining, the Bitmain Antminer S21 XP draws 3245 W while the MicroBT Whatsminer M66S draws 3441 W. The Bitmain Antminer S21 XP uses 196 W less power, which at $0.07/kWh saves ~$120 per year in electricity.

Can both the Bitmain Antminer S21 XP and MicroBT Whatsminer M66S mine the same coins?

Yes — both units can mine Bitcoin (BTC) and Bitcoin Cash (BCH). You can switch between these coins with a simple pool configuration change.

Which unit has a better ROI?

ROI depends on hardware acquisition price, electricity cost, and coin price trajectory. The more efficient unit (better J/TH or hashrate per watt) will generally have a lower operating cost per coin mined, but the absolute ROI timeline is determined by the purchase price. Always model both units in the MiningReturns calculator with your specific electricity rate and current market prices.

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Calculate real profitability

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