Antminer ASIC Miners: From S9 to S23

Bitmain Antminers have shaped Bitcoin ASIC mining by pushing two core metrics: hash rate per unit and joules per terahash. If you are upgrading, valuing used rigs, or planning rack space, it helps to view the lineup through real constraints: rising power costs, higher network difficulty, and cooling that now drives site design. Next is a clear guide to S9 through S21, plus the S23 direction.

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S9 Series: The Workhorse Era

The Antminer S9 is the one people still bring up when they talk about durability. Released around 2016 and 2017, it used 16 nm BM1387 chips and typically delivered about 13 to 14 TH per second. Power draw landed around 1300 to 1400 watts, putting efficiency near 95 to 100 J per TH.

Those numbers are not competitive for most Bitcoin mining today, but the S9 earned its reputation the old fashioned way: it ran for years, it was easy to understand, and parts were everywhere. That long service life is also why you still see S9 units on secondary markets and in odd setups where the heat output is as useful as the hashing.

S17 Series: Efficiency Jump, Reliability Lessons

In 2019 the S17 generation arrived with a 7 nm chip design and a big efficiency leap. Hash rates moved into the 50 to 60 TH per second range, often at 2200 to 2500 watts, which comes out around 45 J per TH. That was a real cut in power cost per terahash compared with the S9 era.

The tradeoff was that early batches of S17 and related models developed a reputation for higher failure rates than miners were used to. Many units ran fine, but the generation never became the “run it forever” legend the S9 did. Today, used S17 units show up cheaply and can still make sense in very low power cost environments or for hands on operators who can repair and manage them.

S19 Series: The Modern Baseline

The S19 generation, spanning roughly 2020 to 2022, became the backbone of many serious mining fleets. A typical S19 landed around 95 TH per second at about 3250 watts, roughly 34 J per TH. The S19 Pro pushed around 110 TH per second at similar power, closer to 30 J per TH.

Later, the S19 XP moved into 5 nm class silicon and reached around 140 TH per second at about 3010 watts, roughly 21.5 J per TH. That number matters because efficiency buys survival time when revenue per TH shrinks. It also helps explain why S19 variants remain attractive on resale markets: they are often the cheapest hardware that still has a realistic chance of working at mainstream electricity prices.

Cooling stayed largely air based, but builds were generally more consistent than the S17 era, with steady parts availability and familiar maintenance routines.

S21 Series: Efficiency Gets Serious, Cooling Starts to Split

The S21 line pushed efficiency into a new tier. Air cooled models are commonly discussed around 200 TH per second at roughly 3550 watts, about 17.5 J per TH. That kind of step change makes older fleets look expensive to operate in comparison, especially after a halving.

S21 is also where cooling starts to feel like a defining choice rather than an accessory. Hydro cooled variants push performance further and hold efficiency near 16 J per TH, but they also make the infrastructure conversation unavoidable. Water cooling means different plumbing, different failure modes, and a different approach to deployment, but it can also make very high power density practical.

S23 Series: The Direction of Travel

The S23 discussion is about two things: extremely high hash rate per unit, and single digit J per TH targets. Early specs talked around the industry for hydro cooled S23 units point toward roughly 580 TH per second at about 5.5 kW, around 9.5 J per TH.

If that class of hardware becomes widely deployed, it will widen the efficiency gap enough that older models will feel pressure quickly. Not overnight, because the network absorbs hardware over time, but the economics start to favor the most efficient fleets in a way that is hard to ignore.

It also reinforces a trend: at the top end, air cooling becomes less practical. Heat is not just a byproduct now, it is the design center.

Quick Comparison Table

These are typical, commonly cited ranges. Exact numbers vary by specific sub model, firmware settings, and operating mode.

Antminer generation	Approx hash rate	Approx power	Approx efficiency	Typical cooling
S9	13 to 14 TH/s	1300 to 1400 W	95 to 100 J/TH	Air
S17	50 to 60 TH/s	2200 to 2500 W	Around 45 J/TH	Air
S19 Pro class	Around 110 TH/s	Around 3250 W	Around 30 J/TH	Air
S19 XP	Around 140 TH/s	Around 3010 W	Around 21.5 J/TH	Air
S21 air	Around 200 TH/s	Around 3550 W	Around 17.5 J/TH	Air
S21 hydro	300 plus TH/s range	5 kW plus range	Around 16 J/TH	Hydro
S23 hydro direction	Around 580 TH/s	Around 5.5 kW	Around 9.5 J/TH	Hydro

What to Watch When You Choose a Generation

Electricity price first, always. Hardware decisions get much clearer once you know your real all in cost per kWh.
Cooling is a budget line, not a detail. Moving from air to hydro changes infrastructure, staffing, and failure planning.
Used market value is about efficiency, not nostalgia. S9 is famous, but efficiency decides whether it earns.
Parts and repair access matter more as hardware ages. A cheap unit that cannot be serviced is usually not cheap.
Firmware can keep a fleet flexible. Tuning options can let you trade speed for efficiency and stabilize units in tough conditions.

Where Vnish Fits Into This

Hardware generation is only half the equation. Firmware decides how that hardware behaves under real constraints. Stock firmware is generally built to be safe across many environments, but it often leaves performance and efficiency potential unused, especially when you need to match machines to a specific electricity price or cooling setup.

VNish custom firmware is widely used across major Antminer models, including older fleets like S9 and S17 and more modern units like S19 and beyond, because it opens up practical control points.

What operators usually care about:

Tuning flexibility

You can tune for higher output when power is cheap, or tune for efficiency when power is expensive. That is the difference between running and shutting off in many regions.

Thermal behavior and stability

Fan curves, temperature targeting, and smarter handling of unstable boards can help keep miners online through hotter seasons and imperfect conditions.

Monitoring and fleet management

Better visibility into errors, temps, and board behavior makes it easier to spot problems early and apply consistent settings across many units.

Extending usable life

For older models, the goal is not to pretend they are modern. It is to squeeze them into a useful role, sometimes by dropping power draw and keeping them stable.

Final Take

S9 proved miners could run for years. S17 proved efficiency jumps can come with reliability lessons. S19 became the modern baseline that still makes sense on many resale lists. S21 pushed efficiency into a tier that changes post halving planning. S23 points toward a future where single digit J per TH and liquid cooling define the top end.

If you want the shortest path to a sensible decision: start with power cost, then choose the most efficient generation your cooling and budget can support, then use VNish to tune and stabilize that hardware for your specific conditions.

Frequently Asked Questions

Clear answers to common questions about VNISH firmware and usage

Why are Bitmain Antminers considered the benchmark for Bitcoin mining?

Antminers consistently pushed improvements in hash rate per unit and energy efficiency. Across generations, Bitmain hardware set the reference points farms use to plan power, cooling, and capacity.

Are Antminer S9 units still useful today?

S9 miners are no longer competitive at typical electricity prices, but they still appear in secondary markets and niche setups. In very low power cost environments or where heat reuse matters, they can still have a role.

What went wrong with the S17 generation?

The S17 series delivered a major efficiency jump but suffered from higher than expected failure rates in early batches. Many units run fine, but the generation earned a reputation for reliability issues compared with the S9 and S19 lines.

Why is the S19 series still common in mining farms?

S19 models balance solid efficiency with manageable power draw and air cooling. They remain attractive on resale markets because they are often the lowest cost machines that can still operate at mainstream electricity prices.

How does the S21 change mining infrastructure planning?

S21 pushes efficiency much lower in joules per terahash, but also makes cooling a core design choice. Hydro cooled variants increase power density and performance while requiring more complex infrastructure.

What is the significance of the S23 direction?

Early S23 expectations point toward extremely high hashrate per unit and single digit joules per terahash. If widely deployed, this level of efficiency will increase economic pressure on older hardware generations.

How does firmware like VNish affect Antminer viability across generations?

Firmware tuning allows operators to trade speed for efficiency, manage thermals, and stabilize aging hardware. This flexibility can extend the useful life of older miners and help newer models adapt to real world power and cooling constraints.