Michal Beno3 November 2026 · Miner Anatomy
1What is inside the box?
From the outside, a Bitcoin miner looks like a loud metal brick with fans on each end. Inside, it is a tightly packed computer built for one task: running the SHA-256 hash function trillions of times per second. That single focus is why it is called an ASIC, short for application-specific integrated circuit. A laptop can do many jobs slowly; an ASIC does one job extremely well.
Every modern Bitcoin miner has the same six main parts. Knowing them helps a buyer read a spec sheet, understand a repair ticket, and see why hosting matters.
2Hashboards and ASIC chips: the engine
A hashboard is a long circuit board covered in rows of small ASIC chips, each bolted under a heat sink or a cold plate. Many air-cooled models carry three hashboards side by side. Each chip makes guesses, and the hashboard adds them up. The total across all boards is the hashrate printed on the label, such as 188 TH/s for the Antminer S21. One TH/s is one trillion guesses per second.
Because the work is split across boards, one failed board does not stop the whole miner. It just lowers the hashrate. That is useful to know when reading the app.
| Full hashrate | 188 TH/s |
| Hashrate lost (one third) | about 62.7 TH/s |
| Hashprice estimate | about 3.5 cents per TH per day |
| Revenue lost per day (62.7 x $0.0353) | about $2.21 |
| If left unfixed for 10 days | about $22 |
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In the catalogue Antminer S21
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3Efficiency: how much power each terahash needs
Chip design decides efficiency, measured in joules per terahash (J/TH). It means how much energy the miner spends to make one trillion guesses. Lower is better, because electricity is the biggest running cost.
| 24 J/TH |
| 21.5 J/TH |
| 17.5 J/TH |
| 15 J/TH |
| 9.5 J/TH |
| 8.9 J/TH |
The newest hydro models need roughly half the energy per terahash of an S21. For a deeper ranking, see the most energy-efficient ASIC miners.
4The control board: the brain
The control board is a small computer, often tucked at one end of the case. It runs the firmware, which is the software that tells the chips how fast to run, reads temperature sensors, and talks to the mining pool. It also hosts the web page technicians use to set the pool address. When a miner is tuned to save power or push more hashrate, the change happens here.
Control boards rarely break on their own. Most 'brain' problems are fixed with a firmware reflash or a settings check, which a hosting team can do remotely or at the rack.
5The power supply: where wear starts
The power supply unit, or PSU, takes power from the grid and turns it into the low, steady voltage the hashboards need. It works hard every second of every day, so it runs warm. Together with fans, the PSU is one of the parts most likely to need a swap over the life of a Bitcoin miner.
Here is a simple fact that surprises many buyers: almost every watt a miner uses ends up as heat. So the power draw also tells you how much heat the site must remove.
| Rule | 1 watt = about 3.412 BTU of heat per hour |
| Antminer S21 (3,290 W) | about 11,225 BTU per hour |
| Antminer S23 Hyd (5,349 W) | about 18,251 BTU per hour |
| Whatsminer M79S (14,502 W) | about 49,481 BTU per hour |
6Cooling: fans or water plates
Air-cooled miners push air through the case with fans, usually two at each end. Fans spin fast, make noise, pull in dust, and their bearings wear out with time. Hydro miners replace fans with water plates: metal blocks with channels that carry liquid across the chips. The warm liquid flows to a chiller or dry cooler, gives up its heat, and comes back cool.
| 49.5k BTU/h |
| 18.3k BTU/h |
| 12.9k BTU/h |
| 11.2k BTU/h |
Hydro units handle much more heat per box, run quieter, and have fewer moving parts inside. The trade-off is that they need a water loop, which only makes sense at facility scale. Read more in air, hydro or immersion.
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In the catalogue Antminer S23 Hyd
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7The network port and why uptime is the real metric
The last part is the humble network port. A Bitcoin miner only earns while it is online and connected to its pool. A loose cable earns nothing. That is why uptime, the share of time a miner is hashing, matters as much as any chip.
| Days in a year | 365 |
| Offline days at 98% uptime | about 7.3 days |
| Offline days at 95% uptime | about 18.3 days |
| S23 Hyd revenue estimate per day | about $19.85 |
| Revenue gap between 98% and 95% | about 10.95 days x $19.85 = about $217 a year |
8Who looks after all these parts?
Compare sites on the hosting page, or check common questions in the FAQ.
9Frequently asked questions
This article is for education only and is not financial advice. Mining revenue depends on the Bitcoin price, network difficulty, fees, power costs and uptime, all of which change. Figures are estimates based on public network data and rates listed on oneminers.com on 30 October 2026; check the live pages for current rates and prices.
