Summary
- CM9 E3.S SSD variants are designed for direct liquid cooling using a cold plate.
- The models can also work in conventional air-cooled server environments.
- The CM9 series is sampling to selected customers; performance figures are vendor specifications, not independent cooling tests.
Kioxia has introduced E3.S versions of its CM9 enterprise solid-state drives designed for servers with direct liquid cooling and cold-plate thermal interfaces. Kioxia makes the SSDs; server and cooling-system designers must provide the cold plate, mounting arrangement and coolant circuit. The company announced the addition through its European and Japanese operations on 13 October and says samples are going to selected customers.
Direct-to-chip cooling removes heat from processors and other high-power components, but storage devices still need a predictable thermal path through the server enclosure. If a server enclosure has substantially less airflow because its central processors are cooled by liquid, SSD temperatures cannot simply be assumed to remain within specification.
The E3.S form factor is one of the enterprise drive formats used in dense server layouts. Supporting a cold plate lets designers consider a direct conduction path from the storage device to liquid-cooled equipment, although the detailed mounting arrangement, mechanical tolerances and coolant circuit still have to be designed as part of the server.
Integrating storage into a liquid-cooled server
A cold plate collects heat through a conductive interface and transfers it to circulating coolant. That reduces dependence on moving a large volume of air across the device, but the thermal interface, contact pressure, flow rate and coolant temperature all affect performance. The drive still needs appropriate monitoring and a safe operating envelope.
Kioxia says the new CM9 direct liquid cooling models can also support conventional air-cooled environments. That could give server manufacturers some flexibility when planning related product configurations, though interchangeability between any two server systems should not be assumed without mechanical and electrical qualification.
Dense AI infrastructure places substantial demand on data storage for training datasets, checkpoints and retrieval workflows. The storage subsystem is therefore part of a wider balance between I/O throughput, capacity, power and cooling. A storage drive that is easier to integrate thermally does not by itself guarantee faster AI training or improved overall facility energy efficiency.
The announcement does not establish energy savings for a complete rack or building, and it does not provide an independently verified comparison against equivalent air-cooled installations. Such outcomes depend on the server enclosure and facility cooling plant as well as the SSD. Energy may still be consumed by pumps, heat rejection and auxiliary systems.
Kioxia says the CM9 series is sampling to selected customers for functional checks and cautions that sample specifications may change before mass production. Kioxia has not published a broad shipping volume, customer deployment list or operating fleet statistics for the new cooling variants. The products are being demonstrated during the 2026 Open Compute Project Global Summit, but a trade-show exhibit should not be confused with commercial commissioning.
Cooling a drive through a cold plate can also alter service procedures. Technicians may need to disconnect or isolate part of a liquid circuit before replacing a storage component, depending on the host server’s design. That can affect the maintainability expected of frequently serviced storage arrays. The announcement does not settle whether particular server designs will allow hot-swapping without disturbing coolant connections. Server manufacturers will have to balance component density with practical repair and replacement requirements.
Kioxia quotes up to 14.8GB/s sequential read and 11GB/s sequential write for CM9 under specified test conditions; these are manufacturer performance specifications, not independent cold-plate validation or facility energy-saving results. The cold-plate option remains a server-integration choice awaiting wider customer qualification.
