OWC 32GB DDR4 2133MHz CL15 ECC Registered RDIMM 288pin 1.2V memory upgrade for Lenovo Flex System x240 M5

32GB DDR4 ECC RDIMM for Lenovo Flex System x240 M5

This 32GB DDR4 2133MHz CL15 module is built for the Lenovo Flex System x240 M5 server. It uses registered ECC technology to protect data integrity in workloads that cannot tolerate silent corruption. The 288-pin RDIMM runs at 1.2V and is organised as a 2Rx4 dual-rank part. It replaces Lenovo part numbers 00FC888, 4X70G88311, 95Y4808 and 95Y4810.

Registered ECC cannot mix with unbuffered memory

Registered ECC DIMMs require a memory controller that supports buffering and error correction; standard desktop boards and consumer laptops lack that support. Mixing this module with unbuffered memory will prevent the system from booting or cause instability. The PC4-17000 rating sets the maximum transfer rate at 2133 MT/s, so the module will not exceed that speed even if the platform allows higher frequencies.

Tool-less insertion into 288-pin DDR4 slots

Align the notch on the module with the key in the slot and press firmly until both retention clips engage; no screws or cables are required. The most common error is seating the DIMM unevenly, which leaves one clip open and causes a memory detection failure. Because the module has no heat spreader, ensure the chassis airflow meets the server’s thermal specification. Verify the system firmware is current before installation to avoid compatibility issues with registered DIMMs.