Samsung 128GB DDR5-4800 ECC RDIMM (M321RAGA0B20-CWK) – 2S2Rx4 3DS Server Memory

128GB per slot on DDR5 servers for AI, HPC, and large databases.

The Samsung M321RAGA0B20-CWK is a 128GB DDR5-4800 ECC Registered DIMM using stacked 3DS DRAM in a 2S2Rx4 layout. It lets Intel Xeon 4th/5th Gen Scalable and AMD EPYC servers reach 1TB or more per socket for AI and ML pipelines, HPC, and large in-memory databases.

Why DDR5 RDIMMs Matter for High-Core-Count Servers

Current-generation servers have more cores per socket than ever, and each core needs memory bandwidth. DDR5 RDIMMs answer that with higher transfer rates and two independent 40-bit subchannels per module, which keep more requests in flight at once.

DDR5 also moves power regulation onto the module with a dedicated PMIC and adds on-die ECC inside each DRAM chip, in addition to the standard side-band ECC handled by the memory controller. The result is cleaner power delivery and stronger error protection at higher speeds.

This module stacks two DRAM dies per package (2S) to reach 128GB on a standard RDIMM, running at 4800 MT/s and 1.1V.

Memory for AI and ML Pipelines

Training data preparation and inference serving keep large datasets in system memory. 128GB modules raise per-server capacity for these pipelines.

High Capacity Without Extra Servers

Reaching terabyte-class memory per socket reduces the number of servers needed for memory-bound workloads, saving rack space and power.

How to Install the Samsung 128GB Server Memory

1. Shut down the server, disconnect all power cords, and wear an anti-static wrist strap.
2. Open the chassis and follow the vendor’s DIMM population guide so channels are balanced across each processor.
3. Align the module notch with the slot key and press evenly until both ejector latches lock.
4. Power on, allow memory training to finish, and confirm capacity, speed, and ECC status in BIOS or the management controller (iDRAC, iLO, XClarity, IPMI).