11S45D75

The IBM 11S45D75 is the Evaporator Assembly (refrigerated / liquid-cooled heatsink) for high-end IBM zEnterprise systems, primarily the zEnterprise 196 (z196) and zEnterprise 114 (z114) in liquid-cooled configurations.

Product Description

This is a specialized liquid-cooled cold plate and evaporator unit that mounts directly onto the high-power Multi-Chip Modules (MCMs) in the Central Electronics Complex (CEC). It uses chilled liquid (typically facility chilled water or a dedicated cooling loop) to efficiently absorb and remove heat from the processors, providing significantly better thermal performance than traditional air-cooled heatsinks.

In liquid-cooled zEnterprise setups, multiple evaporator assemblies are installed (one per processor book/MCM). The assembly includes:

• Integrated cold plate/evaporator with internal liquid channels
• Quick-connect fittings for the chilled water loop
• Temperature sensors and leak detection circuitry
• Precision mounting hardware and thermal interface material

This component is critical for maintaining safe operating temperatures in dense, high-TDP z196/z114 systems. Failure or leakage can trigger thermal alerts, processor de-configuration, throttling, or protective system shutdown.

Replacement is a major service action that usually requires powering down the CEC and trained IBM service personnel due to the liquid cooling loop.