M321R8GA0BB0-CQKMG Samsung 64GB DDR5 4800Mhz Pc5-38400 SDRAM Ram

Capacity 64GB Density

The "M321R8GA0BB0-CQKMG" indicates a DDR5 module. The "21" denotes an RDIMM (Registered Dual In-Line Memory Module) with ECC, the standard for enterprise servers. "R8" refers to the organization (rank and width). "GA" confirms it's a 64GB module. The "0BB0" segment relates to the component density and revision. Finally, "CQKMG" is the speed and timing suffix: "CQ" signifies DDR5-4800, while "MG" indicates specific CAS latency timings. This meticulous naming allows IT professionals to precisely identify compatibility and performance characteristics. A 64GB module capacity represents a critical balance in today's data center. It enables high memory density per system; a typical dual-processor server with 16 memory slots can reach 1TB of RAM using such modules. This capacity is ideal for consolidating multiple virtual machines, in-memory databases like SAP HANA, or large AI/ML datasets without resorting to more expensive, higher-density alternatives, optimizing both performance and total cost of ownership.

Rank Configuration and System Performance

This module is likely a dual-rank (2R) configuration. Rank refers to an independent set of DRAM chips accessed by the memory controller. Dual-rank modules offer better performance in most server workloads compared to single-rank by improving interleaving, allowing the controller to access data from one rank while another is preparing data. For memory-intensive applications, this translates to sustained higher throughput.

Technologies: ECC and Registration

What truly differentiates server memory from consumer memory are the embedded technologies designed for faultless operation. ECC is non-negotiable for enterprise systems. It detects and corrects the most common types of data corruption—single-bit errors—on the fly, preventing silent data corruption that could crash applications or corrupt databases. The Samsung M321R8GA0BB0-CQKMG module includes dedicated ECC chips that add extra bits to every data word, enabling this real-time correction and ensuring the server's calculations and stored data remain pristine.

Stability

This module is an RDIMM (Registered DIMM). It incorporates a register (or buffer) on the module that sits between the memory controller and the DRAM chips. This buffer handles electrical load, reducing strain on the controller. The primary benefit is scalability. By reducing the electrical load, the memory controller can support more memory modules per channel, allowing servers to be populated with the high-capacity DIMMs needed for enterprise workloads. This comes with a negligible latency penalty (typically one clock cycle) that is vastly outweighed by the gains in capacity and system stability, especially in multi-socket configurations.

4800MT/s and PC5-38400 The Bandwidth Equation

The M321R8GA0BB0-CQKMG "4800MHz" (more accurately 4800 Mega transfers per second, MT/s) refers to the data rate. "PC5-38400" is the module's theoretical peak bandwidth in megabytes per second. It is calculated as (4800 MT/s * 64-bit data bus / 8 bits per byte) = 38,400 MB/s. In a server with an 8-channel memory controller per CPU, the aggregate bandwidth becomes staggering—critical for data-hungry CPUs like Intel Xeon Scalable or AMD EPYC processors.

Reliability 

Samsung is a tier-one manufacturer, producing both the DRAM chips and the finished modules. This vertical integration ensures supreme quality control. Modules like the M321R8GA0BB0-CQKMG undergo exhaustive testing that far exceeds consumer-grade validation. They are tested for extended temperature ranges, signal integrity at maximum load, and long-term durability. They are designed to meet or exceed industry standards from JEDEC and are often subject to additional OEM-specific testing protocols.

Flexibility

Thermal Management and Server Environments

Server DIMMs often include temperature sensors (TS on RDIMMs) for thermal monitoring. In a densely packed server rack, airflow is managed, and these sensors allow the system to proactively throttle or alert if temperatures exceed safe limits, protecting the hardware. Samsung's robust component design ensures stable operation within these demanding thermal envelopes.

Compatibility

Server memory is not one-size-fits-all. Careful attention must be paid to platform and configuration requirements. The Samsung M321R8GA0BB0-CQKMG is designed for next-generation servers based on Intel Xeon Scalable (Sapphire Rapids and later) and AMD EPYC (Genoa and later) platforms that natively support DDR5. It is crucial to consult the server manufacturer's (Dell, HPE, Lenovo, etc.) Qualified Parts List to ensure this specific module is validated for your model. Mixing memory from different vendors or of different speeds can lead to suboptimal performance or boot failures.