Definition
An ASIC chip (Application-Specific Integrated Circuit) is a piece of silicon designed to do exactly one job: compute SHA-256 double-hashes as fast and as efficiently as physically possible. In a Bitcoin miner it is the fundamental computing unit — every other component on the machine exists to feed power, work, and cooling to these chips so they can search for a valid block hash.
Unlike a CPU or GPU, an ASIC cannot run general software. The SHA-256 pipeline is etched directly into the transistors, so the only thing the chip can do is hash. That single-mindedness is what makes it efficient: there are no wasted gates, no instruction decoders, no general-purpose plumbing. Each chip packs hundreds of hashing cores onto a die fabricated at an advanced semiconductor process node, and a miner chains many of them together to reach its rated hashrate.
How chips sit inside a real miner
ASIC chips do not work alone. On every Antminer-class machine they are soldered in long daisy-chained rows across a hashboard, and a typical air-cooled miner carries three hashboards. The control board talks to those chips over an 18-pin signal cable using a UART chain — commands (work) flow forward down the chain, and results (nonces) flow back. Power is delivered through a boost circuit that steps the PSU’s 12–15 V up to roughly 19–25 V depending on the generation, then a ladder of regulators splits it into low-voltage domains shared by small groups of chips.
This domain wiring matters for repair: chips are grouped into voltage domains, not powered individually, so tuning and fault isolation happen per-domain rather than per-chip. Bitmain’s lineup illustrates the spread well:
- BM1387 — Antminer S9 generation, TSMC 16nm, around 75 GH/s per chip at roughly 98 J/TH.
- BM1398 — the S19 family, TSMC 7nm; an S19 carries 76 chips across 38 domains (2 chips per domain), the S19 Pro 114 chips (3 per domain).
- BM1366 — S19 XP and S19k Pro class, TSMC 5nm, around 21.5 J/TH; this is also the chip used in the open-source Bitaxe Supra.
- BM1368 / BM1370 — the S21 generation, TSMC 5nm, reaching roughly 15 J/TH. The S21/T21 runs 108 chips in 12 domains and, notably, dropped the PIC microcontroller used on earlier boards.
The long-term trend is clear: each generation shrinks the process node, raises hashrate per chip, and lowers joules per terahash. That efficiency curve is what decides whether a given machine is still worth running on your power rate.
Why chip health is a repair concern
Because chips are daisy-chained, the chain is only as healthy as its weakest link. When one chip fails — from thermal damage, a manufacturing defect, electrical stress, or a cracked solder joint — it can break communication for every chip downstream of it, dropping a whole board’s hashrate or knocking the chain offline entirely. That is why hashboard diagnostics focus on finding the exact chip where the signal dies along the chain.
Repair at this level is real surface-mount work. Recovering a board means diagnosing the failed chip with a multimeter and chain-test fixture, then reflowing (reheating the existing solder) or reballing (replacing the chip with fresh solder balls) under hot air or an infrared station. It is precise, board-level electronics work — but for high-density modern chips it is often more economical than scrapping an entire hashboard, and it keeps working silicon out of the landfill.
If you are weighing which generation of chip to buy, or trying to revive a board with a dead chain, our team has spent years inside these machines. Compare current hardware on the miners catalog, dig into fault-finding on the ASIC troubleshooting hub, and if you want the chip-level efficiency of a single ASIC in a tinkerable form factor, the Bitaxe hub covers the open-source BM1366/BM1370 boards you can run and repair yourself.
Related terms: ASIC, Hashboard, Control Board, SHA-256, BM1366, BM1370.
In Simple Terms
An individual mining chip that performs SHA-256 hashing. Modern miners contain dozens to hundreds of these.
An ASIC chip (Application-Specific Integrated Circuit) is a piece of silicon designed to do exactly one job: compute SHA-256 double-hashes as fast and as efficiently as physically possible. In a Bitcoin miner it is the fundamental computing unit — every other component on the machine exists to feed power, work, and cooling to these chips so they can search for a valid block hash.
Unlike a CPU or GPU, an ASIC cannot run general software. The SHA-256 pipeline is etched directly into the transistors, so the only thing the chip can do is hash. That single-mindedness is what makes it efficient: there are no wasted gates, no instruction decoders, no general-purpose plumbing. Each chip packs hundreds of hashing cores onto a die fabricated at an advanced semiconductor process node, and a miner chains many of them together to reach its rated hashrate.
How chips sit inside a real miner
ASIC chips do not work alone. On every Antminer-class machine they are soldered in long daisy-chained rows across a hashboard, and a typical air-cooled miner carries three hashboards. The control board talks to those chips over an 18-pin signal cable using a UART chain — commands (work) flow forward down the chain, and results (nonces) flow back. Power is delivered through a boost circuit that steps the PSU's 12–15 V up to roughly 19–25 V depending on the generation, then a ladder of regulators splits it into low-voltage domains shared by small groups of chips.
This domain wiring matters for repair: chips are grouped into voltage domains, not powered individually, so tuning and fault isolation happen per-domain rather than per-chip. Bitmain's lineup illustrates the spread well:
- BM1387 — Antminer S9 generation, TSMC 16nm, around 75 GH/s per chip at roughly 98 J/TH.
- BM1398 — the S19 family, TSMC 7nm; an S19 carries 76 chips across 38 domains (2 chips per domain), the S19 Pro 114 chips (3 per domain).
- BM1366 — S19 XP and S19k Pro class, TSMC 5nm, around 21.5 J/TH; this is also the chip used in the open-source Bitaxe Supra.
- BM1368 / BM1370 — the S21 generation, TSMC 5nm, reaching roughly 15 J/TH. The S21/T21 runs 108 chips in 12 domains and, notably, dropped the PIC microcontroller used on earlier boards.
The long-term trend is clear: each generation shrinks the process node, raises hashrate per chip, and lowers joules per terahash. That efficiency curve is what decides whether a given machine is still worth running on your power rate.
Why chip health is a repair concern
Because chips are daisy-chained, the chain is only as healthy as its weakest link. When one chip fails — from thermal damage, a manufacturing defect, electrical stress, or a cracked solder joint — it can break communication for every chip downstream of it, dropping a whole board's hashrate or knocking the chain offline entirely. That is why hashboard diagnostics focus on finding the exact chip where the signal dies along the chain.
Repair at this level is real surface-mount work. Recovering a board means diagnosing the failed chip with a multimeter and chain-test fixture, then reflowing (reheating the existing solder) or reballing (replacing the chip with fresh solder balls) under hot air or an infrared station. It is precise, board-level electronics work — but for high-density modern chips it is often more economical than scrapping an entire hashboard, and it keeps working silicon out of the landfill.
If you are weighing which generation of chip to buy, or trying to revive a board with a dead chain, our team has spent years inside these machines. Compare current hardware on the miners catalog, dig into fault-finding on the ASIC troubleshooting hub, and if you want the chip-level efficiency of a single ASIC in a tinkerable form factor, the Bitaxe hub covers the open-source BM1366/BM1370 boards you can run and repair yourself.
Related terms: ASIC, Hashboard, Control Board, SHA-256, BM1366, BM1370.