Antminer Z15 Pro: Specs, Profit and vnish Firmware

Why the Z15 Pro is still the Equihash machine people argue about

Zcash does not behave like Bitcoin. The hashrate race is smaller, the hardware choices are narrower, and a single generation of ASIC can stay relevant for years if the coin price and the power bill cooperate. That is the niche the Bitmain Antminer Z15 Pro occupies. It is not a new model in 2026 — Bitmain shipped the first batches around May and June 2023 — but it is still the machine most serious Equihash operators compare everything else against.

Stock, it is rated at 840 KSol/s on Equihash, drawing about 2,780 watts at 25°C, for an efficiency of 3.31 J/KSol. Bitmain allows roughly a 3% swing on hashrate and about 5% on power and efficiency, which is why two identical-looking Z15 Pro units on the same shelf can disagree by a few dozen sols. The coins it is built for are Zcash (ZEC) and Horizen (ZEN). Liquidity, in practice, lives mostly in ZEC.

The argument around this miner is rarely about whether it hashes. It hashes. The argument is whether doubling the older Antminer Z15 is worth the extra circuit, the extra heat, and the used-market price on the day you buy it. Firmware is the part of that argument operators can actually control after the invoice is paid.

What the Bitmain Antminer Z15 Pro actually is

The Antminer Z15 Pro is an air-cooled Equihash ASIC with the power supply built into the chassis. That last detail matters more than it sounds. The original Antminer Z15 needed an external PSU and weighed about 5.9 kg without it. The Pro is a closed box: about 428 × 195 × 290 mm, roughly 16.9 kg with the supply, two high-speed fans, Ethernet on the control board, and a 200–240 V input with a maximum current around 20 A.

Noise at full fan speed is listed at about 75 dB. That is workshop noise, not office noise. Operating temperature is 0–40°C, humidity 10–90% non-condensing. Storage can go colder, down toward −20°C, which only matters if the machine sits in a warehouse between seasons.

Think of it as a specialist, not a general-purpose miner. It will not touch SHA-256 or Scrypt. If the Equihash market softens, you cannot retarget it to Bitcoin. The flip side is the same narrow focus: when ZEC is paying, a purpose-built board usually beats a GPU farm on watts per solution.

Specs that matter on a rack, not just on a datasheet

Public listings sometimes print 840 KSol/s and sometimes 860. Bitmain’s own figure, and the one Vnish documents against, is 840 KSol/s at about 2,780 W. A few comparison pages quote power as low as 2,560 W. Treat 2,780 W as the planning number. Undersizing a breaker because a reseller rounded down is an expensive kind of optimism.

Spec	Bitmain Antminer Z15 Pro
Algorithm	Equihash (ZEC, ZEN)
Hashrate	840 KSol/s (about ±3%)
Power	~2,780 W at 25°C (±5%)
Efficiency	3.31 J/KSol
Release	May–June 2023
Size / weight	428 × 195 × 290 mm, ~16.9 kg
Cooling / noise	2 fans, up to ~75 dB
Input	200–240 V AC, up to ~20 A
Operating range	0–40°C, 10–90% humidity
Daily energy	about 66.7 kWh

Sixty-seven kilowatt-hours a day is the number to tape above the PDU. At $0.05/kWh that is about $3.34 in electricity. At $0.07 it is about $4.67. At $0.10 it is about $6.67. The hashrate does not care which of those bills you pay. Your margin does.

Antminer Z15 vs Z15 Pro

The original Antminer Z15, from 2020, is a 420 KSol/s machine at about 1,510 W and roughly 3.6 J/KSol. The Pro is the straightforward sequel: double the hashrate, not quite double the watts, and a small efficiency gain. You also stop managing a separate power supply.

	Antminer Z15	Antminer Z15 Pro
Hashrate	420 KSol/s	840 KSol/s
Power	~1,510 W	~2,780 W
Efficiency	~3.6 J/KSol	3.31 J/KSol
PSU	External	Integrated
Noise	~72 dB	~75 dB
Best fit	Tighter circuits, smaller tickets	More output per slot

Two Z15 units match one Pro on hashrate and use a bit more power combined (about 3,020 W versus 2,780 W). They also take two network drops, two failure points, and usually more shelf space once the external supplies are counted. One Pro is simpler. Two Z15s can be easier to place if your circuits are 10 A or 16 A and you cannot give a single machine a 20 A feed.

On a hosting bill that charges per kilowatt rather than per chassis, the Pro’s efficiency edge is the whole point. On a home circuit that is already near its limit, the older Z15 is sometimes the machine that actually fits.

Antminer Z15 Pro profitability, without the fairy tale

Profitability calculators in early October 2026 were printing very different daily numbers depending on the ZEC price they snapped and the power rate they assumed. Public trackers clustered roughly around $50–65 a day in gross Zcash revenue for a healthy 840 KSol/s unit, before pool fees. Subtract electricity and a 1–2% pool fee and the net, at industrial power, was often still in the mid-forties to mid-fifties per day. That is a snapshot, not a contract.

Three levers move the result, and none of them sit still:

• ZEC price. Revenue is solutions converted to coins converted to dollars. A quiet week on the chart can erase a month of “ROI math” done on a peak.
• Network difficulty. Your 840 KSol/s is a share of the Equihash network, not a fixed paycheck. More machines online means a smaller share.
• Your kilowatt-hour. At these wattages the power bill is real, but on cheap power it is still a small slice of revenue. The break-even electricity price in recent calculators sat far above typical hosting rates — one October 2026 estimate put the point where profit hits zero near $0.85/kWh. Most farms never see that rate. They do see downtime, pool rejects, and hot aisles, which calculators ignore.

Payback quotes in the wild range from a couple of months to well over a year, because used prices for the Z15 Pro swing hard. A machine bought at a few thousand dollars on a strong ZEC tape looks very different from the same machine bought at the top of a listing. Do the division yourself: purchase price divided by a conservative net day, not by yesterday’s best calculator.

Firmware does not invent coins. It changes the watts you spend to produce them, and how often a tired hashboard takes the whole unit offline. On a 2.8 kW miner, a few percent of efficiency or a few percent of uptime is not a rounding error.

What Z15 Pro firmware from Vnish changes

Vnish spent years on SHA-256 and Scrypt Antminers. Version 1.3.7 is the first release that officially treats the Antminer Z15 Pro as a supported Equihash device. That is the practical meaning of “Vnish Z15 Pro” right now: the same firmware family, pointed at a different algorithm.

In 1.3.7 the useful control is manual. You can set frequency and voltage on the hashboards instead of living on the factory curve. That is what you want when the room is warmer than Bitmain’s 25°C test point, when the circuit is close to its limit, or when one board is healthy and another is not. Lower voltage at a sane frequency often beats a stock profile that looks fine on day one and throttles in July.

Full autotune — the per-chip pass that builds a profile for the boards you actually own — is not in 1.3.7. Vnish has scheduled it for 1.3.8. Until then, the operator is the tuner. That is slower, and it is also honest: you see what the board will hold before you walk away.

Across the rest of the Vnish line, farms already use the web dashboard, pool setup, and Hashcore Toolkit to treat a row of miners as a group instead of thirty browser tabs. Z15 Pro support plugs that Equihash box into the same habit. Installation for this model is NAND, on Xilinx (XIL) control boards, through Toolkit 1.7.5 or newer.

How installation works

This is the short version. The model page has the file picker and the Toolkit notes.

1. Confirm the unit is a Bitmain Antminer Z15 Pro on a Xilinx control board, and that you can reach it on the local network.
2. Install Hashcore Toolkit 1.7.5 or later. Earlier Toolkit builds are not the path for this release.
3. Download the NAND install file for the Z15 Pro from the Vnish model page. Keep a copy of stock firmware if you want a clean rollback.
4. Flash, let the miner reboot, then set pools before you touch frequency. A tuned board pointed at a dead stratum is just a heater.
5. Change frequency and voltage in small steps. Watch chip temperature, share acceptance, and the power draw at the PDU — not only the hashrate badge in the dashboard.

If you run a fleet, Toolkit is also how you avoid updating machines one login at a time. One Z15 Pro is a weekend project. Twenty of them are an afternoon only if the tool can see all twenty.

Power, heat, and the noise nobody budgets for

A Z15 Pro rejects on the order of 9,500 BTU/h. That is a dedicated circuit and a real exhaust path, not a corner of a spare bedroom with the window cracked. Intake air above the high thirties Celsius will show up as fan speed first and hashrate second. The firmware can only tune what the airflow allows.

Plan the electrical side before the overclock. A 2,780 W nameplate on 220 V is already in the mid-teens of amps before power-supply losses and startup. A 20 A breaker with other loads on it is not a 20 A mining circuit. Voltage sag is a classic reason a “stable” profile falls over at 2 a.m.

At 75 dB the machine is fine in a container, a garage with a door that closes, or a hosting aisle. It is a bad roommate. Ear protection is not optional if you are standing in front of a row of them for more than a few minutes.

Used units deserve a boring inspection: fan bearings, dust mats, PSU error history, and whether all hashboards come up. The Pro’s integrated supply is convenient until it is the part that fails. Firmware will not repair a cooked board. It will let you drop frequency on the weak one and keep the other two earning while you wait for parts.

Short answers

Does Vnish support the Antminer Z15 Pro?

Yes. Official support starts in Vnish 1.3.7, with manual frequency and voltage. Autotune is planned for 1.3.8.

What does the Z15 Pro mine?

Equihash. In practice that means Zcash, and Horizen where pools still make sense. It is not a Bitcoin miner.

Is the Z15 Pro twice the Z15?

On hashrate, yes: 840 versus 420 KSol/s. On power, no: about 2,780 W versus 1,510 W, which is why the Pro is the more efficient of the two.

Is it profitable?

At cheap power and a healthy ZEC price, recent calculators say yes, often by a wide margin over electricity. Recheck price, difficulty, and your actual kWh before you buy. A number from last month is not a forecast.

What do I need to install the firmware?

Hashcore Toolkit 1.7.5 or newer, and the NAND install file for the Z15 Pro from the Vnish download page.