IREN Is Switching Off the Business That Made $578 Million
The miner booked a $638.8 million impairment retiring rigs to clear halls for AI tenants. Its $4 billion contracted run rate is still $3 billion above what is actually operating.
·Tom Chen
SHA-256 · air-cooled
Bitmain Antminer S21 Pro
Air-cooled at 15 W/TH, which makes it far easier to deploy than the hydro models while staying competitive on efficiency. At 76 dB from four high-speed fans it is still far too loud for a home without a dedicated, isolated space.
At your electricity rate
$/kWh
Operating profit
$3.85
per day · 0.000114 BTC
Break-even electricity
$0.1057
per kWh · $0.0457 above your rate
Payback period
—
Enter a hardware cost to estimate payback
Revenue / day$8.90
Electricity / day$5.05
Energy / day84.2 kWh
Revenue assumes a 1% pool fee at the current BTC price and network difficulty, with the machine running continuously. Payback needs a hardware cost, which we do not publish because we have no verified retailer feed — add your own purchase price in the calculator. Your rate is saved in this browser and applies across the site.
Specifications
| Manufacturer | Bitmain |
|---|---|
| Model | Antminer S21 Pro |
| Algorithm | SHA-256 |
| Coins | Bitcoin |
| Hashrate | 234 TH/s |
| Power | 3,510 W |
| Efficiency | 15.0 W/TH |
| Cooling | Air |
| Type | ASIC |
| Released | 2024 |
| Home suitable | No — noise and power draw |
| Noise | 76 dB |
| Dimensions | 450 × 219 × 293 mm |
| Weight | 20 kg |
| Operating temperature | -20 to 45 °C |
| Warranty | 365 days |
Data provenance
Manufacturer datasheet as published by retailers; hashrate, power and efficiency corroborated across three independent sources. Last verified 2026-08-03.
Any field not listed above is one we could not verify for this machine. We would rather leave a row out than publish a figure you cannot check. Where published sources disagree, we say so instead of picking one. How we verify specifications.
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