HPE P07991-B21 DL5X0 Gen10 CLX Upper CPU Mezzanine Kit

Overview

The HPE P07991-B21 is the upper CPU mezzanine kit designed for HPE ProLiant DL5X0 Gen10 servers configured with Cascade Lake (CLX) processors. This kit provides the mechanical and electrical interconnect required to seat a second processor in dual-CPU DL5X0 Gen10 configurations — without it, the platform cannot be populated with an additional CPU, making it a required component for any dual-socket upgrade or factory build-out on compatible systems.

Compatibility

This mezzanine kit is specific to the HPE ProLiant DL5X0 Gen10 server family running Intel Cascade Lake (CLX) generation processors. Verify your system's board revision and processor generation before ordering — Gen10 Plus variants and non-CLX processor generations use different mezzanine assemblies and are not interchangeable with P07991-B21. Consult your server's QuickSpecs or service manual to confirm the correct kit for your exact DL5X0 model and CPU stepping.

Installation Notes

Installation requires full system power-down and adherence to HPE's ESD handling procedures. The mezzanine connects directly to the system board; improper seating will prevent CPU recognition at POST. Refer to the HPE ProLiant DL5X0 Gen10 Maintenance and Service Guide for torque specifications, connector alignment guidance, and the correct processor installation sequence when populating both CPU sockets.