OWC 256GB DDR4 3200 CL22 8Rx4 ECC Registered RDIMM memory upgrade

Single-module capacity

This OWC module provides 256GB of DDR4 ECC Registered memory in a single 288-pin RDIMM. It is built for Supermicro server boards including the H12DSG-O-CPU, H12DST-B, H12DSU-iN, H11DSI-NT and H11DST-B. The octal-rank 8Rx4 design targets workstations and servers that require registered ECC DRAM. It will not work in standard desktop computers or alongside unbuffered or load-reduced DIMMs.

Upgrade path

The kit replaces lower-capacity registered ECC DIMMs to maximise memory density per slot on the listed Supermicro platforms. It matches Samsung M393ABG40M52-CAE, Hynix HMAT14JXSRB120N and HMAT14JXSRB122N, and Supermicro MEM-DR425MI-ER32 part numbers. The jump is worthwhile when the workload demands more capacity than smaller RDIMMs can deliver within the same slot count. Builders who need unbuffered memory or load-reduced modules cannot use this product.

Sustained operation

Rated at 3200 MT/s with CL22 latency at 1.2V, the module meets JEDEC PC4-25600 specifications for continuous server duty. ECC correction and registered signalling maintain data integrity during extended multi-threaded workloads. OWC validates every DIMM in-house to ensure reliability under sustained load rather than only in short benchmarks. Mixing capacities, speeds or manufacturers is not recommended for optimal stability.