M321R2GA3PB0-CWMXJ Samsung Memory Module 16GB DDR5 RDIMM PC5-44800

Samsung M321R2GA3PB0-CWMXJ — 16GB DDR5 RDIMM

Upgrade your data centre or enterprise server with the Samsung 16GB DDR5 SDRAM RDIMM. This server-grade memory module delivers high-throughput performance, robust error correction, and industry-standard reliability for mission-critical systems.

Product Specifications

Identification & Manufacturer

• Brand: Samsung
• Model / P/N: M321R2GA3PB0-CWMXJ (also listed as M321r2ga3pb0-cwm)
• Product type: Memory Module / Server RAM

Memory Details

• Capacity: 16GB (1 × 16GB)
• Memory type: DDR5 SDRAM (next-generation synchronous DRAM)
• Speed / Bandwidth: 5600 Mbps — DDR5-5600 / PC5-44800
• Voltage: 1.1V (low-voltage operation)
• CAS latency: CL46 (timing optimized for DDR5)
• ECC support: Yes — error-correcting code for data integrity
• Module classification: Registered (RDIMM) — buffered for server use
• Pin count / Form factor: 288-pin RDIMM
• Rank: Listed in the product name as 1Rx8; technical notes reference 2Rx8 — verify with vendor for exact rank required by your motherboard.

Physical & Shipping Information

Dimensions & Packaging

• Shipping dimensions (approx.): Height: 1.00" × Depth: 6.75"
• Form factor: Standard 288-pin registered DIMM

Key Advantages of this Server Memory Module

• High bandwidth: DDR5-5600 (PC5-44800) for faster data transfer and improved application responsiveness.
• Enterprise reliability: ECC (Error-Correcting Code) support reduces data corruption risk.
• Registered buffering: RDIMM design for stability in multi-module server configurations.
• Energy efficient: Operates at low voltage (1.1V) to reduce power draw in racks.
• Compact form factor: 288-pin RDIMM compatible with standard server memory slots.

Compatibility & Use Cases

Designed for

• Enterprise servers and rack-mounted systems
• Workstations requiring ECC and registered memory
• Database servers, virtualization hosts, and compute nodes

Compatibility

• Confirm motherboard/server vendor lists DDR5 RDIMM and PC5-44800 support.
• Check whether your system requires 1Rx8 or 2Rx8 ranks — mixing incompatible ranks may prevent booting.
• Match voltage (1.1V) and ECC/registered requirements when populating multiple slots.

The Evolution to DDR5: A New Era for Server Memory

The transition from DDR4 to DDR5 memory technology marks a significant leap, not just in raw speed but in architectural philosophy. For servers, this evolution brings forth foundational improvements that directly impact computational throughput and power efficiency.

Key Architectural Advancements in DDR5

DDR5 introduces several core changes that benefit server environments profoundly. The most notable is the move to a dual 32-bit sub-channel architecture per module (from a single 64-bit channel in DDR4). This allows for more efficient data handling and reduced latency for smaller, more frequent access patterns common in server workloads. Furthermore, the power management infrastructure is integrated onto the module itself with the Power Management IC (PMIC), enabling more stable voltage regulation and improved signal integrity—a critical factor for densely populated server racks.

Speed and Bandwidth: The PC5-44800 Designation

The "5600Mbps" and "PC5-44800" labels are intrinsically linked. The data rate of 5600 Megatransfers per second (MT/s) refers to the number of operations the module can perform each second. The PC5-44800 (often called the "PC5 rating") denotes the theoretical peak bandwidth in megabytes per second (MB/s) for the module. Calculated as 5600 MT/s * 8 bytes (width of a DDR channel) / 8 bits per byte, it yields 44800 MB/s. This substantial bandwidth is essential for feeding data-hungry processors in modern servers handling virtualization, large databases, and high-performance computing tasks.

Decoding the Specification: Samsung M321R2GA3PB0-CWMXJ

Every segment of the part number and description conveys critical information about the module's compatibility and capabilities.

Capacity and Configuration: 16GB (1x16GB) 1Rx8

The "16GB (1x16GB)" indicates a single module with a total capacity of 16 Gigabytes. The "1Rx8" configuration is vital for understanding the module's physical memory chip organization. "1R" means Single Rank—the module presents one set of memory chips to the memory controller at a time. "x8" refers to the physical bit-width of each DRAM chip on the module. A 1Rx8 configuration using x8 chips is a common and optimized design for servers, offering a good balance of capacity, signal loading, and performance. It allows systems to populate more modules per channel while maintaining stability, which is crucial for achieving maximum total system memory capacity.

The Pillars of Server Reliability: ECC and Registered Design

These two features are non-negotiable for mission-critical server memory.

ECC (Error-Correcting Code) Memory

ECC is a paramount feature for data integrity. It goes beyond simple parity checking. ECC memory includes extra bits (e.g., 8 bits for a 64-bit word) that allow the memory controller to detect and, most importantly, *correct* single-bit errors on the fly. It can also detect (but not correct) multi-bit errors. This hardware-level correction prevents silent data corruption, software crashes, and system instability caused by cosmic rays, electrical noise, or cell wear-out—risks that are unacceptable in financial, scientific, or cloud infrastructure.

Registered RDIMM (Redundant Dual In-line Memory Module)

The "Registered" or "Buffered" aspect is what defines an RDIMM. A Register (or buffer) is placed between the memory controller and the DRAM chips on the module. This register buffers the command and address signals, reducing the electrical load on the controller. This allows a server motherboard to support a significantly higher number of memory modules—often scaling to multiple terabytes of RAM—without overloading the memory controller's electrical driving capability. The trade-off is an additional clock cycle of latency, which is a minor and acceptable cost for the immense gains in capacity and system stability.

Voltage, Timing, and Form Factor

The "1.1v" operating voltage highlights DDR5's improved power efficiency over DDR4 (typically 1.2v). Lower voltage reduces overall power consumption and heat generation across a server farm, directly impacting operational costs. The "CL46" refers to the CAS Latency, a primary timing parameter (46 clock cycles at the 5600 MT/s speed). While higher in number than DDR4 timings due to the increased speed, the actual time in nanoseconds is comparable or better. The "288-pin" designation specifies the physical interface, which is mechanically different from DDR4's 288-pin layout, preventing incorrect installation.

Target Applications and Use Cases

Samsung DDR5 ECC RDIMMs like the M321R2GA3PB0-CWMXJ are not designed for gaming PCs or general-purpose desktops. They are purpose-built for specific enterprise-grade hardware and workloads.

Compatible Systems and Platforms

This memory module is designed for servers powered by modern platforms such as Intel's Xeon Scalable Processors (Sapphire Rapids, Emerald Rapids, and beyond) and AMD's EPYC 7004 "Genoa" and 8005 "Siena" series processors. These platforms require DDR5 memory and are optimized to leverage the increased bandwidth and advanced features. It is imperative to always consult the server manufacturer's (Dell, HPE, Lenovo, Supermicro, etc.) Qualified Vendor List (QVL) to ensure specific model compatibility, as BIOS and firmware are tuned for validated modules.

Ideal Workloads and Server Roles

The combination of high bandwidth (5600 MT/s), error correction, and high-capacity support makes this memory category ideal for:

Virtualization Hosts (vSphere, Hyper-V): Running dozens of virtual machines requires large pools of reliable, fast memory to handle diverse workloads simultaneously.In-Memory Databases (SAP HANA, Redis): These applications store entire datasets in RAM for ultra-low latency access, demanding both high capacity and unwavering data integrity via ECC.
High-Performance Computing (HPC) & AI/ML: Scientific simulations, financial modeling, and machine learning training involve massive datasets and parallel processing, where memory bandwidth is often the critical bottleneck.
Cloud Infrastructure & Web Tiering: Front-end web servers and application servers benefit from fast memory to reduce response times, while backend cloud infrastructure relies on ECC for uptime and data protection.
Enterprise Resource Planning (ERP) and CRM Systems: Large-scale transactional systems like Oracle Database or Microsoft SQL Server running on servers require stable, high-performance memory to process transactions efficiently.

Samsung's Role in Memory Manufacturing and Quality

Samsung is not merely a vendor but a foundational semiconductor manufacturer. This vertical integration provides significant advantages for enterprise customers.

From Fab to Module: Control and Consistency

Samsung designs and fabricates its own DRAM chips, controls the module assembly process, and conducts rigorous testing. This end-to-end control ensures consistent quality, reliable supply, and optimal compatibility between the DRAM silicon and the module's PCB design. For IT managers, this translates to predictable performance and lower long-term failure rates.

Advanced Technology and Reliability Features

Beyond the standard JEDEC specifications, Samsung often incorporates advanced features into its server modules. These may include enhanced thermal sensors for better cooling management, specialized coatings for improved signal integrity in challenging environments, and strict binning processes to ensure the chips meet the demanding 5600 MT/s speed grade at low voltage (1.1v) with stability.