By Jules Porter | October 10, 2026

Bitcoin mining is an electricity business as much as a computing business. A lower joules per terahash (J/TH) rating means a machine needs less electricity to produce the same hashrate. For an air-cooled mining site, that efficiency difference can determine which ASICs remain profitable when hashprice falls.

These are seven leading full-size, fan-cooled SHA-256 miners ranked by published nominal efficiency as of October 10, 2026. Hydro and immersion machines are excluded. Values are manufacturer ratings or model listings, not independent same-temperature laboratory results. Batch, firmware, operating mode and temperature can change performance; especially for the WhatsMiner M70S+.

The top seven at a glance

1. Bitdeer SEALMINER A4 Pro Air — 10.9 J/TH | 336 TH/s | 3,662 W
2. Bitmain Antminer S23 Air — 11.0 J/TH | 318 TH/s | approximately 3,498 W
3. Bitdeer SEALMINER A3 Pro Air — 12.5 J/TH | 290 TH/s | 3,625 W
4. Canaan Avalon A16XP — 12.8 J/TH | 300 TH/s | approximately 3,850 W
5. MicroBT WhatsMiner M70S+ — 12.9 J/TH in one 244-TH/s listing | approximately 3,140 W; verify your exact bin
6. Bitmain Antminer S21 XP Air — 13.5 J/TH | 270 TH/s | 3,645 W
7. Canaan Avalon A16 — 13.8 J/TH | 282 TH/s | approximately 3,900 W

1. Bitdeer SEALMINER A4 Pro Air — 10.9 J/TH

Bitdeer’s A4 Pro Air takes the top spot with 336 TH/s at 3,662.4 W. The manufacturer’s official listing and A4 launch release both specify 10.9 J/TH. Do not confuse this air model with the A4 Ultra Hydro, whose 9.45 J/TH figure requires liquid cooling.

Sealminer
byu/Just_The_Average_1 inBitcoinMining

2. Bitmain Antminer S23 Air — 11.0 J/TH

The S23 is Bitmain’s high-efficiency fan-cooled flagship. The 318-TH/s specification works out to roughly 3.50 kW at 11 J/TH. Some listings quote a 305-TH/s bin, so confirm the exact model and datasheet rather than combining figures from different versions. The S23 offers a significant efficiency gain over the older S21 XP.

3. Bitdeer SEALMINER A3 Pro Air — 12.5 J/TH

At 290 TH/s and 3,625 W, the A3 Pro Air sits between the latest A4 and Canaan’s A16XP. Bitdeer has published both nominal specifications and a live-test video; the latter reports measurements from a particular operating environment, not a guarantee for every unit.

4. Canaan Avalon A16XP — 12.8 J/TH

Canaan rates the A16XP at 300 TH/s and approximately 3,850 W. The company announced the air-cooled model in October 2025. Its 12.8 J/TH rating is an important improvement for Avalon operators who want to retain familiar air-cooling infrastructure. Read Canaan’s official announcement.

Canaan Inc introduces the Avalon A16 XP
byu/altair_mining inBitcoinMining

5. MicroBT WhatsMiner M70S+ — around 12.9 J/TH

A 244-TH/s M70S+ listing gives 12.9 J/TH and roughly 3,140 W. Other sellers and configurations quote different hashrates and efficiency, including 12.5 and 13.5 J/TH. That variation is material: verify the manufacturer’s exact part number, firmware mode and rated input before treating this as a universal fifth-place result. The video below discusses the wider M70 family, not a certified test of this specific M70S+ bin.

6. Bitmain Antminer S21 XP Air — 13.5 J/TH

The established 270-TH/s S21 XP uses about 3,645 W. Its 13.5 J/TH efficiency is less impressive than the newest models, but it remains an important operational benchmark because of its mature fleet footprint and firmware ecosystem. The S21 generation’s role in replacing older S19 fleets is part of the larger upgrade story.

7. Canaan Avalon A16 — 13.8 J/TH

The standard A16 delivers approximately 282 TH/s while drawing around 3,900 W. Canaan’s 13.8 J/TH rating puts it behind the higher-binned A16XP, but the standard model may cost less up front. The better purchase depends on the delivered price, electricity rate and maintenance history—not just the J/TH figure.

What the efficiency ranking does not tell you

These numbers compare machine-level nominal efficiency, not all-in facility efficiency. Cooling fans outside the machine, transformers, electrical losses and hot-air recirculation increase the site’s actual energy cost. See our guide, Your ASIC’s J/TH Is Not Your Site’s J/TH, and our MicroBT versus Canaan fleet comparison.

For example, a miner rated at 11 J/TH uses about 18.5% less electricity per terahash than one rated at 13.5 J/TH, before facility overhead. But a lower purchase price, stronger uptime or cheaper repairs can offset an efficiency disadvantage. Profitability is not identical to power efficiency; see our separate profitability ranking at $0.08/kWh.

Methodology: Full-size, commercially marketed, fan-cooled SHA-256 ASIC models; one representative rated configuration per product; sorted from lowest to highest nominal J/TH. This is a selected leading-model ranking rather than an independently certified census of every possible bin, firmware setting or low-power mode. Manufacturer specs: Bitdeer A4, Bitdeer A3, Canaan A16 series; comparative specifications: MinerList and ViaBTC’s testing-conditions discussion. Figures checked October 10, 2026.