SoftBank–Foxconn H200 rack cooling pilot

Project brief

What is publicly known

Status: pilot. SoftBank, ZutaCore, and Foxconn reported that they operated and evaluated one rack-scale system at a SoftBank data center in February 2025. Foxconn built the server around NVIDIA H200 graphics processing units, ZutaCore supplied HyperCool two-phase direct liquid cooling, and SoftBank integrated the rack.

The partners say the server passed NVIDIA's NVQual temperature test and that the rack achieved a measured partial power usage effectiveness of 1.03. That ratio means the measured cooling scope used about three units of power for every hundred units attributed to computing. It is not whole-building power usage effectiveness, and the source does not publish the test boundary or raw data.

Cooling relevance comes from integration. The dielectric fluid boils in cold plates on processors, graphics processors, and memory, then condenses in the loop. SoftBank also designed the rack around 19-inch and Open Rack version 3 equipment, rear power and cabling, and future robotic handling.

This is stronger evidence than a concept announcement because hardware ran and a result was reported. It is still supplier and partner evidence from a controlled demonstration. Unknowns include rack kilowatts, test duration, inlet and return temperatures, load profile, redundancy, failure behavior, service procedure, fluid loss, and whether the system carried production work.

The release says the parties will pursue commercialization, which confirms that the demonstrated design was not yet a generally deployed product. A named production site, customer order, commercial warranty, repeat test by an independent lab, or sustained workload data would strengthen the status. Broad rollout should require several commissioned racks and operating evidence.

A result that cannot be reproduced at full load would weaken the efficiency claim without erasing the fact that the pilot occurred.

Status is labeled from public evidence. Supplier orders, MoUs, pilots, projects under delivery, and operating sites are not counted as equivalent.