OWC 256GB (8×32GB) DDR4 2400 CL17 2Rx4 288-pin 1.2V ECC Registered RDIMM memory upgrade

Cisco HX server upgrade

This 256GB kit contains eight 32GB DDR4 2400 ECC registered RDIMM modules built for the Cisco HX220c M4 and HX240c M4. Each stick runs at 1.2V with CL17 latency and a 2Rx4 organisation. The registered design adds a buffer that stabilises the memory bus in multi-DIMM server configurations. It will not work in standard desktop boards or alongside unbuffered or load-reduced memory.

Sustained server workloads

Registered ECC memory corrects single-bit errors on the fly and keeps the command bus stable when all eight slots are populated. The 2Rx4 layout spreads each 32GB module across two ranks, letting the memory controller interleave requests across ranks during long compute or virtualisation runs. CL17 timing at 2400 MT/s delivers predictable latency without the voltage headroom that consumer overclocking modules require.

DDR4 2400 interface limits

The PC4-19200 standard caps transfer rate at 2400 MT/s, so bandwidth per channel is fixed regardless of module count. Adding more DIMMs increases capacity but not peak throughput, and the registered buffer adds one cycle of address latency. Systems that need higher memory bandwidth must move to a platform supporting faster DDR4 speeds or a newer memory generation.