The Antminer S19 and the Antminer S21 are the two Bitmain models we get the most questions about. The S19 is the cheapest way into Bitcoin mining. The S21 costs more but uses about half the energy for every terahash. Which one makes sense for you depends mostly on one number: what you pay for electricity.
Below we compare the specs, show the electricity price at which each model still earns more than it costs to run, and explain when the S19 is still the better buy.
Antminer S19 vs S21 at a glance
| Antminer S19 | Antminer S21 | |
|---|---|---|
| Hashrate | 95 TH/s | 175 TH/s |
| Power draw | 3,250 W | 3,062 W |
| Efficiency | 34 J/TH | 17.5 J/TH |
| Algorithm | SHA-256 (Bitcoin) | SHA-256 (Bitcoin) |
| Cooling | Air | Air |
| Power supply | Included | Included |
| Price (excl. VAT) | €349,- | from €1.099,- |
The S21 delivers 84% more hashrate while drawing slightly less power. That is the whole story in one line: per unit of electricity, the S21 mines almost twice as much Bitcoin.
Why efficiency matters more than hashrate
Efficiency is measured in joules per terahash (J/TH): how much energy a miner needs to produce one terahash. Lower is better. The S19 needs 34 J/TH, the S21 needs 17.5 J/TH.
Your mining revenue depends on hashrate and the network’s hashprice. Your costs depend almost entirely on power. When the hashprice drops or your electricity bill goes up, an inefficient miner stops being profitable first. An efficient one keeps running.
Break-even electricity price per model
The simplest way to compare miners is the electricity price at which a miner earns exactly what it costs to run. Below that price you make money. Above it, you lose money on every day the miner runs.
We calculated this with a hashprice of $39.63 per PH/s per day, the level of 6 September 2026. Revenue is before pool fees and the purchase price of the miner is not included.
| Model | Hashrate | Power | Revenue per day | Break-even power price |
|---|---|---|---|---|
| Antminer S19 | 95 TH/s | 3,250 W | $3.76 | $0.048 per kWh |
| Antminer S19 Pro | 110 TH/s | 3,250 W | $4.36 | $0.056 per kWh |
| Antminer S19k Pro | 120 TH/s | 2,760 W | $4.76 | $0.072 per kWh |
| Antminer S19 XP | 141 TH/s | 3,010 W | $5.59 | $0.077 per kWh |
| Antminer S21 | 175 TH/s | 3,062 W | $6.94 | $0.094 per kWh |
| Antminer S21+ | 235 TH/s | 3,877 W | $9.31 | $0.100 per kWh |
| Antminer S21 Pro | 245 TH/s | 3,510 W | $9.71 | $0.115 per kWh |
| Antminer S21 XP | 270 TH/s | 3,645 W | $10.70 | $0.122 per kWh |
The pattern is clear. At this hashprice, an S19 only covers its power bill below roughly 5 cents per kWh. An S21 still breaks even at about 9 cents. Every step up in efficiency gives you more room for a higher power price or a lower hashprice.
The hashprice moves every day with the Bitcoin price, network difficulty and transaction fees. Use the table to compare models, not as a promise of future earnings.
When the Antminer S19 still makes sense
- Your power is very cheap. Below about $0.05 per kWh, for example with your own solar, hydro or curtailed energy, the low purchase price of the S19 can win.
- You reuse the heat. If the 3,250 W of heat replaces a heater in a workshop, greenhouse or home, part of the power cost pays for itself.
- You want to learn first. At €349,- excl. VAT, the S19 is a low-risk way to learn how mining, pools and maintenance work before you invest in newer hardware.
Looking for the lowest entry price of all? Check our tested second-hand ASIC miners.
When the Antminer S21 is the better choice
- You pay a normal commercial power price. If your electricity costs more than about 5 cents per kWh, the S21 is the safer buy. It keeps mining at a profit in conditions where an S19 already runs at a loss.
- You plan to mine for several years. Each Bitcoin halving and every rise in network difficulty pushes older, less efficient machines out first.
- You have limited power capacity. On the same 3 kW connection, an S21 produces 175 TH/s against 95 TH/s for the S19.
The middle ground: S19k Pro and S19 XP
Between the two sit the S19k Pro (23 J/TH) and the S19 XP (21.5 J/TH). They cost less than an S21 and are far more efficient than the original S19. If your power price sits around 6 to 7 cents per kWh, they are worth comparing. Above the S21, the S21+, S21 Pro and S21 XP push efficiency down to 13.5 J/TH for operators with higher power prices. The next step is the Antminer S23, coming soon to our range: 318 TH/s at 3,498 W, or 11 J/TH. That makes it the most efficient air-cooled Antminer so far.
Practical differences
- Power supply: both come with the power supply included. You need your own power cords: for the S19, two cords rated at 10 A or more.
- Noise: the S21 is rated at 76 dBA. Like every air-cooled Antminer, neither model is suitable for a living room without a silencer or a separate space.
- Size: the S21 measures 400 × 195 × 290 mm and weighs 15.4 kg.
- Warranty and repairs: we offer up to 2 years of warranty, and repairs are handled at our repair center in the Netherlands, so you don’t have to ship your miner to Asia.
Frequently asked questions
Is the Antminer S19 still profitable in 2026?
Only with cheap power. At a hashprice of $39.63 per PH/s per day, the S19 breaks even at about $0.048 per kWh. Above that, it costs more to run than it earns.
How much more efficient is the S21 than the S19?
The S21 needs 17.5 J/TH, the S19 needs 34 J/TH. That makes the S21 almost twice as efficient: it mines about 94% more Bitcoin per kWh.
Should I upgrade from an S19 to an S21?
If your S19 runs at a loss or close to break-even, yes. The S21 produces almost twice the hashrate from the same power connection. If your power is very cheap, keeping the S19 running can still make sense.
Should I wait for the Antminer S23?
The S23 (11 J/TH) breaks even at about $0.15 per kWh, so it gives you the most room if your power is expensive. If you want to start mining now, the S21 is available today and already profitable up to about $0.09 per kWh. Contact us to reserve an S23.
Order from the Netherlands
Both models ship from our warehouse in the Netherlands, with no import duties for EU customers. Compare the full range on our Bitmain Antminer page, or contact us for a quote on multiple units. Interested in the new Antminer S23? Contact us and we will let you know as soon as it arrives.
