What is the Supermicro In-Rack CDU?
Supermicro's in-rack coolant distribution unit puts the heat exchanger inside the rack it serves, which shortens the loop and lowers the pressure the pumps must overcome. It occupies 4U and is rated to 250 kW, enough for one dense rack. Supermicro states operation on water up to 45 degrees Celsius, which removes the mechanical chiller from the critical path, and pairs that with a claim of up to 98 percent heat capture per rack when the whole DLC-2 stack is used. The remaining few percent still leaves through air, so the room cannot be treated as thermally neutral. Two variants are listed: an EIA model with 2N redundant pumps drawing up to 1.2 kW, and an OCP model with N+1 pumps drawing up to 3 kW. Dimensions are 480 by 810 by 177 mm and 480 by 858 by 177 mm respectively, at 100 and 114 kg dry. Power supplies are redundant. Management runs over Redfish, SNMP, a web interface and Supermicro's own orchestration software. An in-row unit at 1.8 MW is also offered for multi-rack pods. Supermicro does not publish the approach temperature, the flow rate, the secondary fluid, or the pressure drop, so the 250 kW figure cannot be compared directly with a rival quoted at a named approach.