Antminer S21 Series — The Most Powerful Miners on the Market in 2025
As the year draws to a close, the profitability record undoubtedly goes to the Antminer S21 series, which marks a new stage in the evolution of Bitcoin mining machines.
Developed by Bitmain, this generation reaches, with its most powerful model, a computing power that can exceed 245 TH/s, with an energy efficiency of around 15 joules per terahash — a record for the industry.
This model illustrates the current trend: ever more powerful machines that are also more energy-efficient. In practice, this cuts electricity costs while maintaining a high level of security on the Bitcoin network.
However, users should consider several factors before any purchase:
• the quality of the power supply,
• the ambient temperature,
• and the cost per kWh in their region.
The Antminer S21 has now become an interesting case study in energy optimisation in mining.
We bring the whole series together in our Antminer S21 collection, including the Antminer S21 XP 270 TH/s, so you can compare the models.