OWC 2L9D44R41TBK 1024GB (8×128GB) DDR4 2933 CL21 ECC LRDIMM memory upgrade

Server memory kit

This OWC kit delivers 1024 GB of DDR4 2933 ECC load-reduced memory across eight 128 GB LRDIMM modules. It is built for Cisco UCS B200 M5, B480 M5, C220 M5, C240 M5 and C480 M5 servers that require 288-pin registered DIMMs with 4Rx4 organisation. The modules operate at 1.2 V and carry a CL21 latency rating. Buyers who need unbuffered or standard registered ECC memory cannot use this kit.

Upgrade path

The kit replaces Cisco part number UCSML128G4RTH and supports backward-compatible speeds of 2133, 2400 and 2666 MT/s. It is intended for administrators expanding capacity in the listed UCS M5 platforms or refreshing older modules that run at lower DDR4 frequencies. The jump is worthwhile when the server’s memory controller and BIOS recognise load-reduced DIMMs and the workload demands the full 1024 GB configuration.

Build fit

Each module is a 288-pin LRDIMM without a heat spreader, so the server’s standard airflow must provide adequate cooling. The load-reduced design reduces electrical load on the memory bus, freeing electrical headroom for the maximum supported DIMM population. Mixing with unbuffered or standard registered ECC DIMMs is not supported, so all slots in a channel should be populated with matching load-reduced modules.