OWC 64GB (4x16GB) DDR4 2400 CL17 ECC Registered RDIMM Cisco UCS B420 M4 C460 M4

Server memory kit

This OWC kit provides 64 GB of DDR4 2400 ECC registered memory in four 16 GB modules. It is built for Cisco UCS B420 M4 and C460 M4 servers that require registered DIMMs with error correction. The modules run at 1.2 V with CL17 latency and a 1Rx4 organisation. They will not work in standard desktop computers or alongside unbuffered or load-reduced memory.

Replaces Cisco UCSMR1X161RVA and UCSMR1X161RVG

The kit directly replaces those Cisco part numbers for field upgrades or fresh deployments. It is worth installing when the existing configuration uses smaller registered DIMMs and the workload needs more capacity for virtualisation or large datasets. Systems already populated with matched registered modules of the same speed and rank can be expanded without mixing memory types.

DDR4 2400 registered ECC constraints

Registered ECC DIMMs add a clock cycle for buffering, so latency is higher than unbuffered equivalents at the same data rate. The 2400 MT/s JEDEC standard caps bandwidth at PC4-19200, limiting throughput for memory-bound tasks. Capacity scaling depends on the server memory controller and available DIMM slots, which are not detailed here.