SoftBank Corp., ZutaCore and Foxconn collaborate

SoftBank Corp., ZutaCore and Hon Hai Technology Group (“Foxconn”) have implemented ZutaCore's two-phase DLC (Direct Liquid Cooling) technology in an AI server using NVIDIA accelerated computing, making it the world’s first implementation of ZutaCore's two-phase DLC (Direct Liquid Cooling) technology using NVIDIA H200 GPUs. In addition, SoftBank designed and developed a rack-integrated solution that integrates each component of the server, including cooling equipment with two-phase DLC technology, on a rack scale, and conducted an operational demonstration and performance evaluation at its data center in February 2025. The demonstration results indicated the solution passed NVIDIA's temperature test (NVQual), thereby confirming the compatibility, stability and reliability of this rack-integrated solution. The solution also achieved pPUE (partial Power Usage Effectiveness) of 1.03 (actual measured value) per rack for cooling efficiency.

With the spread and increased adoption of AI, demand for AI servers and other computing resources is expected to expand significantly, further increasing power consumption at data centers. At the same time, reducing power consumption from the perspective of reducing carbon dioxide (CO2) emissions has become a pressing issue worldwide, requiring data centers to become more efficient, consume less power, and introduce innovative heat removal solutions. Since May 2024, SoftBank has been collaborating with ZutaCore, a global leader in the development and business deployment of two-phase DLC technology, to develop solutions optimized for low power consumption at AI data centers.

SoftBank, ZutaCore and Foxconn will continue their efforts to achieve higher efficiency and lower power consumption in AI data centers using NVIDIA accelerated computing, and collaborate on the development of rack-integrated solutions optimized with two-phase DLC technology for practical use and deployment in the global market.

Features of rack-integrated solution optimized with two-phase DLC technology

1. Plug & Play solution

By integrating server components such as cooling equipment equipped with 2-phase DLC technology, which conventionally had to be optimized individually, on a rack scale, it is possible to provide a “Plug & Play”*4 solution that can be used immediately by simply connecting the equipment. This makes it easy and simple to install in AI data centers.

2. Innovative 2-phase DLC cooling system

ZutaCore's two-phase DLC technology, which cools the chipsets (CPUs, GPUs, memory, etc.) that are the heat sources in the server by bringing them into contact with a cold plate, circulates a special insulating heat transfer (dielectric) fluid with a low boiling point in the cold plate and uses heat absorption during the phase change from liquid to gas caused by the heat source. Efficient cooling is achieved through repeated evaporation and condensation. In addition, the water temperature can be maintained at a higher temperature than in conventional water-cooled facilities, which improves the heat transport capacity of the water used for cooling and reduces the flow rate of water to achieve the required cooling effect. This makes it possible to reduce the pressure of the pump that delivers the water for cooling, contributing to lower power consumption. Furthermore, the use of insulating heat transfer fluid prevents serious damage to the server in the event of a spill of special fluid.

3. AI server with guaranteed compatibility, stability and reliability

Foxconn developed an AI server based on NVIDIA H200 GPUs, optimized with ZutaCore's two-phase DLC technology. This AI server was able to exceed target performance figures in NVIDIA's certification test (NVQual), which determines the compatibility, stability, and reliability of server systems.

4. Versatile and scalable rack for high-density placement of AI servers

SoftBank developed a rack designed to maximize cooling efficiency and improve operational efficiency with its two-phase DLC technology. In addition to being designed to be versatile and scalable for high-density placement of the latest AI servers, the rack has airflow for improved cooling efficiency, and power supply. In addition, power supply and wiring are concentrated in the rear of the rack for operational safety and robot-friendly operation. The rack is also compatible with 21-inch servers and conventional 19-inch servers compliant with the ORV3 standard, which is a specification set by the Open Compute Project (OCP), a non-profit organization that promotes open-source hardware specifications and designs. The specifications are designed to be deployed in accordance with global standards.

Future Developments

SoftBank, ZutaCore, and Foxconn will strengthen cooperation with AI server and rack design companies to improve the efficiency and low power consumption of AI data centers using NVIDIA accelerated computing, with a view to the commercialization of this solution and its deployment in the global market.