Hashboard: what it is and how it works
A hashboard is a printed circuit board populated with ASIC chips that does the actual mining in a miner – it calculates hashes. An air-cooled Antminer usually has three hashboards, and the machine's hashrate is the sum of theirs. If one board fails, the miner keeps mining, but roughly a third slower.
How a hashboard works
The chips on the board are connected one after another in a chain. The control board sends them work, the chips calculate and return results. The power supply feeds the board, the heatsink with fans removes heat and two temperature sensors make sure it does not overheat.
Example: the Antminer S21 with 200 TH/s has three boards with 108 BM1368 chips each, 324 chips in total. That works out at about 67 TH/s per board. If one board fails, the machine delivers roughly 133 TH/s and uses about a third less power.
| Model | Chip | Chips per board | Number of boards | Total chips |
|---|---|---|---|---|
| Antminer S19 | BM1398 | 76 | 3 | 228 |
| Antminer S19 Pro | BM1398 | 114 | 3 | 342 |
| Antminer S19 XP | BM1366 | 110 | 3 | 330 |
| Antminer S21 | BM1368 | 108 | 3 | 324 |
| Antminer L7 | BM1489 | 120 | 4 | 480 |
Typical hashboard faults
- Broken chain: a faulty chip stops passing the signal on, so the firmware only “sees” the chips before it. If it reports 29 out of 76 chips, the fault is at chip 30.
- Board not detected: the machine does not find it at all. The cause is usually the connector, the board's power supply or a faulty circuit on the board.
- One board overheating: dried-out thermal paste, a loose heatsink or dust.
- Corrosion: after operation in humidity or with condensation, green or white deposits appear on the joints.
You can hardly repair a hashboard at home without a diagnostic fixture and a soldering station. In our service centre in Prague we diagnose boards and replace faulty chips. What to do with other faults is described in the article ASIC miner faults.
Why it matters for miners
Hashboards are the most expensive and most sensitive part of a miner. With a used machine, always check the hashrate of each board separately and the chip count in the log – more in the guide New or used ASIC. A replacement board must match the model, the chip type and the board revision; a board from a different model will usually not work.
Related terms
- What is an ASIC miner – what other parts the machine consists of.
- ASIC miner lifespan – why boards age over time.
What next
To make the boards last as long as possible, follow the guide ASIC miner maintenance – clean, cool air matters most to them.
Sources
Frequently asked questions
Can I add another hash board to a miner?
Does a miner mine with only two of its three boards?
Can I use a hash board from a different model?
How do I recognise a faulty hash board?
This text was prepared with the help of AI. Facts, figures and procedures were checked by Yegor.
