Antminer S19j Pro+

The Antminer S19j Pro+ is Bitmain’s efficiency-tuned SHA-256 miner, rated at 117 TH/s for about 3,355 W (roughly 28.68 J/TH at stock). Built on the 5nm BM1362 ASIC across three 126-chip hashboards, it is a previous-generation workhorse: cheap to acquire, easy to service, and a capable space heater.

Chip and hashboard architecture

The S19j Pro+ runs the BM1362, a TSMC 5nm « small-die » SHA-256 ASIC that carries four large hashing cores per chip. Each of the three hashboards is populated with 126 chips, for 378 chips in a fully populated unit. That high chip count on a mature 5nm process is what lets the S19j Pro+ undercut the older 7nm S19/S19 Pro on energy per terahash while staying on the same physical platform.

Compute is orchestrated by Bitmain’s X19-class control board. On the FPGA-based revision this is a Xilinx Zynq-7000 (XC7Z007S) system-on-chip — dual ARM Cortex-A9 cores at 667 MHz paired with programmable logic that runs the per-chain UART and work-distribution FPGA design. The control board streams work to each chain, collects nonces, and relays I2C telemetry from the power and temperature controllers. Later S19j-series units shipped instead on a BeagleBone-class (TI AM335x) control board that handles ASIC communication in software with no FPGA — a distinction worth confirming before you plan a firmware change, because aftermarket firmware coverage differs between the two boards.

Voltage domains, not per-chip control

A common misconception is that each ASIC is tuned individually. It is not. The chips on every hashboard are grouped into voltage domains — clusters wired in series that share one regulated rail. The domain voltage equals the per-chip core voltage multiplied by the number of chips in that domain, so voltage is set per domain, never per individual chip. A shared-rail PSU (Bitmain’s APW12-class, ~13.5 V on the main rail) feeds the boost and domain regulators, and a dsPIC33 power-controller relays voltage and current readings back to the control board over a single I2C bus it shares with the temperature sensors. Stock firmware drives the whole board from that shared rail; there is no per-chain voltage trim on a factory S19j Pro+.

Thermals are watched by a TMP451 sensor on each board plus the on-die temperature reading inside every BM1362. Bitmain’s firmware targets roughly 60 °C on the PCB, treats ~80 °C as hot, and trips protection near 90 °C board / 110 °C chip junction. Four fans in a dual-tunnel airflow path move the heat, which is also why this is a loud machine at full tilt.

Real-world power and efficiency

Nameplate numbers and wall numbers are not the same thing. At its stock 117 TH/s the S19j Pro+ pulls about 3,355 W at the wall for ~28.68 J/TH, but the BM1362 platform has a wide, well-characterized tuning curve. D-Central catalogs 21 power profiles for this model — see the full curve on our ASIC power profiles database. A representative slice:

The striking detail is the bottom of the curve: undervolted to ~65–75 TH/s the S19j Pro+ reaches 22–23 J/TH, comfortably better than its stock efficiency and competitive with newer hardware in absolute energy terms. If your priority is profit per kilowatt-hour rather than raw hashrate, the efficient operating point sits well below the nameplate. Push the other way and the curve is unforgiving — past ~140 TH/s efficiency climbs above 33 J/TH, so overclocking only makes sense where power is genuinely cheap or where you specifically want the extra heat. At stock the unit dumps roughly 11,447 BTU/h, enough to meaningfully warm a workshop or basement.

Firmware compatibility

Out of the box the S19j Pro+ runs Bitmain’s stock firmware, which is stable but offers limited tuning beyond a few preset modes. Because the BM1362/X19 platform is so widespread, it is also one of the most thoroughly supported targets for third-party firmware, which is where the granular auto-tuning behind the curve above comes from. Note that an auto-tuner calculates each operating point at runtime against the silicon’s measured behavior — those values are computed live, not pulled from a fixed preset list.

Two honest caveats. First, native Stratum V2 support is rare: among the available open-source firmwares, only Braiins OS+ ships it natively, so if end-to-end V2 matters to you, confirm the firmware actually implements it rather than assuming. Second, firmware options depend on the control board — FPGA-based Zynq units enjoy the broadest coverage, while BeagleBone-class units are more limited. D-Central’s own DCENT_OS — our GPL-3.0, open-source Antminer firmware — targets this BM1362 platform; it is in closed beta today, with a public beta planned for summer 2026, and is part of our broader effort to keep these machines self-hostable rather than dependent on any single vendor. We credit the open-source firmware projects that proved this ground before us; DCENT_OS is one more layer of decentralization, not a replacement for them.

Common faults and troubleshooting

Most S19j Pro+ failures show up as a hashboard that comes up with fewer than its 126 expected chips, a chain that drops to zero, or a unit that throttles and restarts under load. Because the chips are series-wired into domains, a single point of failure usually takes a region offline rather than one chip:

• Reduced ASIC count on a chain (e.g. 86/126) — a broken chip or open domain interrupts the daisy-chain, so every chip downstream of the fault stops reporting.
• Zero hashrate on one board — a shorted domain collapses its rail; the boost regulator may fold back to protect the PSU, or the control board fails to detect the chain entirely.
• Temperature / sensor errors — a failed TMP451 or a clogged heatsink trips the thermal cutoff well before the silicon is actually in danger.
• Won’t start / no chain detected — control-board, PSU-handshake, or cabling issues rather than the hashboards themselves.

Work through symptoms systematically with our ASIC fault finder, which maps error codes and behaviors to likely causes for the S19 family. Before condemning a board, measure the domain test points: an abnormal voltage between domains points to a specific failed chip or its domain regulator. One platform-specific warning — do not reset the dsPIC power controller on these units as a troubleshooting step; on the S19j series that is a one-way downgrade, not a fix.

Repair and longevity

The S19j Pro+ is a genuinely repairable machine, and that is central to why it remains worth owning. D-Central has run an in-house ASIC repair lab in Laval, Québec since 2016, and we service this model down to the component level: domain diagnosis, BM1362 chip reballing and replacement, regulator and PSU work, and control-board recovery. A 5nm board with a couple of dead domains is usually an economic repair, not scrap — see our ASIC repair service for turnaround and what we can fix. Treated well (clean air, sane temperatures, and tuning kept off the aggressive end of the curve), these units run for years, which is exactly why a healthy secondary market exists for them.

Who it’s for and buying

The S19j Pro+ suits two buyers especially well. The first is the cost-sensitive miner who wants real terahash without flagship pricing and is happy to undervolt for 22–24 J/TH where power costs matter. The second is the heat-reuse miner: with a home-mining score of 84/100 and ~11,447 BTU/h of recoverable heat, it makes a credible — if loud, at ~75 dB — supplemental heater for a garage, workshop, or grow space, ducted away from living areas. Browse current ASIC stock in our ASIC miners catalog or the full D-Central shop. If 3.3 kW and 75 dB are simply too much for your space, a low-power open-source option like the DCENT_axe is a better entry point into self-hosted mining — it won’t pay an electricity bill, but it teaches the whole stack at a few watts.

Generational context

The S19j Pro+ is a 2022, fourth-generation Antminer — the efficiency-optimized sibling of the standard S19j Pro, tightening energy-per-terahash at a similar hashrate by leaning harder on the 5nm BM1362. It sits between the 7nm S19/S19 Pro it improved on and the 5nm BM1366 generation (S19k Pro, S19 XP) and the later BM1368-based S21 that followed it.

Figures above are representative stock/nameplate values; every one of these models has a full tuning range documented in our power profiles database. In 2026 the S19j Pro+ is no longer a frontier machine, but its combination of low acquisition cost, strong undervolt efficiency, recoverable heat, and component-level repairability keeps it one of the more sensible ways to put hashrate on the network — or to keep an existing fleet alive long past its warranty.