OWC 256GB (4x64GB) DDR4 2933 CL21 ECC RDIMM memory upgrade

System-Specific Server Memory

This OWC kit provides 256 GB of DDR4 ECC registered memory across four 64 GB modules. It is built for Cisco HX220c M5, HX240c M5, HXAF220c M5, HX-E-220M5SX and C480 ML M5 servers. The modules run at 2933 MHz with CL21 latency and 1.2 V operation. They are not compatible with standard desktop computers.

Compatibility Check

Verify that your server model appears in the supported list before ordering. The memory uses a 288-pin registered DIMM form factor with 2Rx4 organisation and cannot be mixed with unbuffered or load-reduced ECC modules. Backward compatibility covers 2133, 2400 and 2666 MHz speeds. Replacement part numbers include HXMRX64G2RTH and UCSMRX64G2RTH.

Thermals and Power

Modules operate at the standard 1.2 V DDR4 voltage without integrated heat spreaders. Registered buffering reduces electrical load on the memory controller during sustained workloads. ECC circuitry adds minimal overhead while correcting single-bit errors. No active cooling is required beyond normal server airflow.