Avalon A1246

The Avalon A1246 is Canaan’s 2021 air-cooled SHA-256 workhorse, rated at 90 TH/s for about 3,420 W (roughly 38 J/TH). Built on the 12th-generation Avalon ASIC and a RISC-V Kendryte K210 control board, it is a previous-generation industrial miner that still earns its keep on cheap power or as a heat source.

Chip and hashboard architecture

The A1246 belongs to Canaan’s A12 series (12th generation, 2021). Canaan designs its SHA-256 silicon in-house — a lineage that traces directly back to the Avalon 1 of 2013, the first Bitcoin ASIC ever shipped — and the A1246 runs the A3200-family chip used across the A11/A12 platform. Canaan has never published the exact process geometry for this part, so we will not guess at a node figure: what matters in practice is that it sits a couple of generations behind the TSMC 5 nm silicon Canaan later moved to in the A15/A16 chips, which is why its efficiency reads « older-gen. »

Each hash board carries 120 chips arranged in 40 groups of three in parallel, wired as series chains across the board. The A1246 delivers its 90 TH/s across Canaan’s standard three-board A12 chassis. This series-chain topology is worth understanding before you ever open the lid: because the chips in a group sit in an electrical chain, a single failed die can take its whole group — and sometimes a larger sub-chain — offline, which is why a dead chip on an Avalon often shows up as a step-down in board hashrate or a low ASIC count rather than a clean single-chip fault.

The Kendryte K210 control board

Where Antminers run an ARM Cortex-A9 on a Xilinx Zynq SoC, the A1246 is driven by Canaan’s own Kendryte K210 — a dual-core 64-bit RISC-V SoC on TSMC 28 nm, clocked up to 400 MHz with roughly 8 MB of on-chip SRAM (6 MB general + 2 MB AI) and no external DDR. That tiny memory footprint means the control board runs FreeRTOS bare-metal, not Linux, and there is no SSH shell in stock firmware. Communication to the hash boards is direct SoC-to-board over SPI; there is no FPGA sitting between controller and chips, and there is no PIC microcontroller on the hash boards the way there is on an Antminer.

Power on each board is split into separate voltage domains — a variable Vcore plus fixed VTOP (~0.75 V) and VDDIO (~1.8 V) rails — with 12 V from the PSU boosted to around 17.7 V internally on the board. Voltage is controlled per domain, directly by the SoC over SPI, not per individual chip and not through a PIC. Each board also carries two 10K NTC thermistors (TH1/TH2) for thermal monitoring. The practical upshot is a control architecture that is genuinely simpler than an Antminer’s at the protocol level, but far more locked down at the firmware level.

Real-world power and efficiency

The 3,420 W nameplate is measured at the board; at the wall you should budget a few percent more for PSU conversion loss, so plan for roughly 3,600 W on a dedicated 200–240 V circuit (the A1246 will not run on standard North American 120 V). At 38 J/TH, the A1246 lands squarely in the previous-generation efficiency tier — competitive against the Antminer S19 and Whatsminer M30S era of 2020–2021, but well behind anything 5 nm. That math is the whole story for this miner: it makes sense where electricity is cheap, or where the roughly 11,669 BTU/h of waste heat is doing double duty warming a space.

Tuning headroom is modest and honest. The stock firmware exposes a workmode setting (normal versus performance) that trades a little more power for a little more hashrate, and Canaan’s privileged API can nudge frequency and voltage — but none of this turns a 38 J/TH machine into an efficient one, and aggressive settings void Canaan’s warranty. For where the realistic tuning envelope sits on this class of hardware, see our ASIC power profiles database. Treat the A1246 as a fixed-efficiency machine you site around cheap energy, not one you tune your way to profitability.

Firmware compatibility

Out of the box the A1246 runs Canaan’s stock MM (Miner Manager) firmware with a CGMiner 4.11.1 fork underneath. You get a web dashboard on port 80 (config-mode default IP 192.168.168.168), the standard CGMiner JSON API on port 4028 for monitoring and pool control, and a Windows-based AvalonMiner upgrade tool for firmware. Monitoring stacks such as pyasic and most ASIC management toolboxes speak to it over that same port-4028 API.

The honest third-party reality is short: there is no aftermarket firmware for the A1246. BraiinsOS+, VNish, LuxOS and ePIC all target Antminer (and in some cases Whatsminer) hardware — none of them support Avalon. The K210’s bare-metal FreeRTOS environment, with no Linux and no shell, is a fundamentally different and much harder target than an ARM-Linux Antminer, which is why no custom-firmware community has formed around the industrial K210 Avalons. Our own DCENT_OS firmware work centres on Antminer-class hardware; the K210 industrial Avalons remain research territory, not a supported flash target, and we would rather tell you that plainly than oversell it. If you want to tune an A1246, you are working within Canaan’s stock workmode and privileged API — nothing more.

Common faults and troubleshooting

The A1246’s failure modes track its architecture. The most common is reduced or zero hashrate from a hash board: because the chips run in series groups, one dead die drops a whole group, so the symptom is usually a board reporting a low ASIC count or a chunk of missing terahash rather than a clean single-chip error. Other frequent calls are thermal and fan faults (the dual-fan, 75 dB cooling system is the first thing to check when boards throttle or shut down), PSU faults, and a hash board that fails to be detected at boot.

Work through symptoms methodically with our ASIC fault finder, which maps observed behaviour to likely root cause, and cross-reference any on-screen or API status text against our error-code library. Many « dead miner » cases on this platform are a single failed group, a tired fan, or a thermistor reading out of range — not a write-off.

Repair and longevity

D-Central has been repairing ASICs in-house in Laval since 2016, and the A1246 is firmly in our wheelhouse — we maintain published repair documentation for the closely related AvalonMiner 1146, and that A11/A12-family knowledge carries straight across. Board-level work on the A1246 includes diagnosing and reflowing or replacing failed chips in a series group, testing the Vcore/VTOP/VDDIO domains and the internal boost stage against their test points, and chasing fan, thermistor and PSU faults. Because the control board has no PIC and no FPGA, much of the diagnostic complexity that bogs down Antminer repairs simply isn’t present here — the hard part is chip-level board work, which is exactly what a proper repair bench is for.

An A1246 that is kept clean, cool and on a healthy PSU has years of useful life left as a low-cost or heat-reuse machine. If yours has dropped a board or stopped hashing, see our ASIC repair service before retiring it.

Who the A1246 is for

This is a machine for operators with genuinely cheap power, for heat-reuse setups where the ~11,669 BTU/h is a feature rather than a cost, and for hobbyists who want a real industrial miner on a secondhand budget. It is not the right pick if you are chasing efficiency — at 38 J/TH it will be outrun on any normal power tariff by newer hardware. If efficiency is your priority, compare it against current-generation models in our miner comparison tool and browse the full ASIC miner database. And if what actually draws you to the A1246 is the idea of hacking on open mining hardware, a Bitaxe-class open-source miner is a far better tinkering platform than a locked-down K210 Avalon. Units and current pricing live in our shop.

Generational context

Canaan occupies a respected place in mining history: the Avalon 1 was the first Bitcoin ASIC to ship, and the company has designed its own SHA-256 silicon ever since. The A1246 was the 2021 flagship of the air-cooled A12 line, going head-to-head with the Antminer S19 and Whatsminer M30S. Canaan has since iterated steadily — the table below shows how the A1246 sits against the generations that followed, culminating in the 5 nm A15 silicon that finally closed much of the efficiency gap to Bitmain.

Avalon A1246 specifications at a glance

Specifications and architecture details above are cross-checked against D-Central’s internal Bitcoin mining hardware reference. For live profitability math and side-by-side comparisons, use the calculators on this page and our comparison tool.