Antminer S19K Pro Specs

The Antminer S19K Pro is one of the most efficient air-cooled members of Bitmain’s S19 line, released in late 2023 on the TSMC 5nm BM1366 chip. It delivers about 120 TH/s at roughly 2,760 W, for an efficiency near 23 J/TH. That combination — strong efficiency at a comparatively low price — is why the S19K Pro became a popular home and hosted-mining choice, and it is the basis for D-Central’s own 120 V "Slim Edition" mod. This guide gives the real specs and internals, written from D-Central’s bench experience with the S19 family.

Antminer S19K Pro specifications, explained

Hash rate

The S19K Pro hashes at about 120 TH/s of SHA-256 (some batches are rated slightly higher). It is worth being precise here: the S19K Pro is a 5nm BM1366 machine in the ~120 TH/s class — it is not a 136 TH/s miner, a figure sometimes mis-listed online by borrowing numbers from the older 7nm BM1398 generation. On a used unit, confirm all three boards report full chip counts before trusting the nameplate.

Power and efficiency

At roughly 2,760 W the S19K Pro’s efficiency lands near 23 J/TH at 25°C ambient — strong for the S19 line and one of the reasons it sold well into home and small-scale operations. It still trails the S21 generation (15–17.5 J/TH), but at a much lower purchase price. It expects 200–240 V AC with about a 20 A draw, so a dedicated 240 V circuit and a quality PDU are recommended.

Chip and hash-board architecture

The S19K Pro is built on the TSMC 5nm BM1366 — the same chip family as the S19 XP and S19 XP Hydro. The chips are spread across three hash boards and, as on every Antminer, grouped into series-wired voltage domains regulated as units. Voltage is controlled per domain, not per individual chip, so a single failed chip silences its whole domain and chain — the first thing to check when diagnosing a dead board.

Cooling and environment

Two high-static-pressure fans cool the boards. The S19K Pro is rated for 0–40°C and 10–90% non-condensing humidity; keeping it cool, dust-free, and well-ventilated is the cheapest way to protect those 5nm boards. Like every full-size Antminer it is loud and belongs in a shed, garage, or dedicated space.

The S19K Pro and 120 V: the Slim Edition

Because the S19K Pro is relatively efficient and modestly priced, it is a natural candidate for home use — but its stock 200–240 V input is a barrier on standard North American 120 V outlets. D-Central’s S19K Pro Slim Edition is a hand-built modification that reconfigures the unit for lower power and 120 V operation, making it more practical for residential setups and small spaces. It is one example of D-Central’s modded-Antminer work; tested, warrantied units appear in our shop as they are built. The same machine remains at home anywhere from a home setup to a professional hashcenter, depending on how it is configured.

Custom firmware on the Antminer S19K Pro

The S19K Pro is a common target for third-party firmware. Custom firmware does not change the silicon — it changes how the control board drives it. The headline feature across the firmware ecosystem is autotuning: instead of running every chip at one factory frequency, the firmware finds an efficient operating point and applies it per voltage domain, not per individual chip. The values are calculated live from each board’s measured behaviour rather than loaded as fixed presets.

On the S19K Pro, autotuning is commonly used to underclock for a 120 V power budget, to push efficiency further, or to trim heat and noise. This category exists thanks to the projects that built it in the open — Braiins pioneered ASIC autotuning and the Stratum V2 protocol, with a broader community carrying it forward. Our firmware comparison lays out the trade-offs honestly, including dev fees and what each project actually open-sources.

D-Central’s own contribution to that lineage is DCENT_OS, a GPL-3.0 open-source Antminer firmware we are building in the open. It is in closed beta today, with a public beta targeted for summer 2026 — experimental, not production-ready. You can join the DCENT_OS waitlist to follow or test it. We stand on the shoulders of the people who opened this space first.

Owning and repairing an S19K Pro

We have repaired, refurbished, and modded S19K Pro units on our Laval bench since they launched. When a board drops a chain or a unit stops hashing, we publish transparent flat-rate ASIC repair pricing instead of the opaque return-for-repair loop the manufacturers run, and — because the S19K Pro is still genuinely useful — repair is often worthwhile here. Whether running an S19K Pro pencils out depends on your electricity rate and current network difficulty; we keep our profitability and comparison tools current so you can run the numbers yourself rather than trust a static estimate.

FAQ

What is the Antminer S19K Pro?

The Antminer S19K Pro is a SHA-256 ASIC miner from Bitmain for mining Bitcoin and other SHA-256 coins. Built on the TSMC 5nm BM1366 chip, it produces about 120 TH/s at roughly 2,760 W, for an efficiency of about 23 J/TH.

What chip does the S19K Pro use, and is it really 136 TH/s?

It uses Bitmain’s TSMC 5nm BM1366 — the same family as the S19 XP — and is a ~120 TH/s machine. The occasionally-seen 136 TH/s figure is incorrect; it borrows a number from the older 7nm BM1398 generation.

What power supply does the Antminer S19K Pro require?

It expects 200–240 V AC and draws about 2,760 W (around 20 A). A dedicated 240 V circuit and a high-quality PDU are recommended for safe, stable operation.

Can the S19K Pro run at home on 120 V?

Not in stock form — it expects 200–240 V. D-Central’s S19K Pro Slim Edition is a hand-built modification that reconfigures the unit for lower power and 120 V operation for residential use.

Can the Antminer S19K Pro run custom firmware?

Yes. Autotuning firmware adjusts frequency and voltage per voltage domain at runtime — useful for fitting a 120 V power budget or improving efficiency. D-Central is also building DCENT_OS, an open-source (GPL-3.0) firmware currently in closed beta.