Bitmain’s New 860TH/s Liquid Cooled Rack-Mounted Bitcoin Miner Built with Hut 8
Hut 8 and Bitmain have announced the launch of the Antminer U3S21EXPH, an ASIC miner featuring direct liquid-chip cooling within the U form factor. Hut 8 plans to deploy this model in Q2 2025 via a hosting agreement, which will allow it to scale its managed hashrate to approximately 33.5 exahashes per second (EH/s).
The U3S21EXPH represents a significant advancement in ASIC computing by incorporating cooling technologies commonly used in high-performance computing data centers. This miner transitions from a traditional “shoebox” design to a rack-ready U form factor, allowing for deployment densities of up to approximately 180 kilowatts per rack. Hut 8 aims to develop custom data center infrastructure to accommodate this new hardware, optimizing performance and efficiency.
The most powerful miner on the market today is the Bitmain S21 Pro, which operates at 234TH/s. The new miner is 3 times more powerful and 3 J/TH more efficient.
According to the announcement, the partnership between Hut 8 and Bitmain extends beyond procurement. The two companies have collaborated on technical and commercial aspects, with Hut 8 contributing to the development of the miner.
The hosting contract features a fixed hosting fee and gives Hut 8 the option to purchase some or all of the hosted machines within 6 months of activation. This structure is designed to reduce upfront capital requirements and allow Hut 8 to evaluate market conditions before investing additional funds. If Hut 8 fully exercises this option, its own mining hash rate could increase from 5.6 EH/s to approximately 20.6 EH/s.
Irene Gao, Bitmain’s VP of Mining, acknowledged Hut 8’s role in the development process, noting the company’s focus on cost-effective procurement and operations. The collaboration is seen as a natural evolution of their relationship to define the future of mining technology.
Asher Genoot, CEO of Hut 8, highlighted the innovative nature and benefits of the hosting agreement, saying:
“Our team worked closely with BITMAIN to implement an innovative architecture for commercialization of U3S21EXPH before it could be released to the broader market.”
The deployment of U3S21EXPH and the associated hosting agreement represent a strategic move for Hut 8. By incorporating advanced cooling technologies and a flexible procurement strategy, the company seeks to improve operational capabilities and financial performance.
