Samsung M321R2GA3BB0-CQKMG 16GB PC5-38400 RDIMM ECC Registered DDR5 RAM

The Samsung M321R2GA3BB0-CQKMG 16GB DDR5 Registered DIMM is a high-performance server-grade memory solution engineered to deliver superior reliability, faster speeds, and efficient multitasking. With DDR5 technology, enhanced bandwidth, and ECC error correction, it ensures stability and long-lasting performance in data-intensive environments.

Key Information

• Brand: Samsung
• Part Number: M321R2GA3BB0-CQKMG
• Product Type: DDR5 Memory Module

Key Features at a Glance

• Capacity: 16GB (1 x 16GB)
• Speed: 4800 Mbps (DDR5-4800 / PC5-38400)
• Form Factor: 288-Pin RDIMM
• Voltage: 1.1V power-efficient design
• ECC: Error-Correcting Code for dependable data integrity
• Latency: CL40
• Rank: 1Rx8 structure

Advanced DDR5 Technology

Compared to previous generations, DDR5 SDRAM brings a substantial leap in speed and efficiency. The Samsung 16GB DDR5 Registered Memory Module provides:

• Up to 4800 Mbps transfer rates for faster data throughput
• Increased bandwidth to support high-demand applications
• Optimized multitasking performance for enterprise workloads
• Better power management with a 1.1V operating voltage

ECC and Reliability Enhancements

The inclusion of Error-Correcting Code (ECC) ensures that data integrity is maintained, minimizing system crashes and improving uptime. With ECC and registered signal buffering, this module is perfectly suited for critical servers, workstations, and enterprise applications.

Physical Specifications

• Module Type: RDIMM (Registered DIMM)
• Pin Count: 288-pin standard design
• Dimensions: 1.00” height x 6.75” depth
• Weight: Approx. 0.20 lbs

Reason of Choose Samsung DDR5 RDIMM

Samsung is a leader in memory innovation, providing cutting-edge solutions that combine performance with durability. Choosing this DDR5 16GB Registered DIMM means benefiting from:

• Server-grade reliability and performance consistency
• Future-proof design with DDR5 standards
• Lower latency (CL40) optimized for real-time processing
• Scalability for data centers and high-performance computing

Applications and Use Cases

This memory module is ideal for environments where speed, stability, and accuracy are crucial:

• Enterprise servers requiring constant uptime
• High-performance computing clusters
• Workstations for professional workloads such as AI, ML, CAD, and data analytics
• Cloud storage systems and virtualization platforms

Performance Benefits in Detail

With its registered buffering and ECC support, the Samsung M321R2GA3BB0-CQKMG reduces electrical load on memory controllers, increasing system stability. The 1Rx8 rank architecture ensures faster access times and streamlined performance in multi-threaded environments.

Highlights of the Samsung M321R2GA3BB0-CQKMG DDR5 Module

• High-speed 4800 Mbps transfer rate
• ECC functionality to safeguard data accuracy
• Durable design for continuous enterprise-level use
• Energy-efficient 1.1V operation
• Optimized for modern servers and data center environments

Technical Breakdown

• Technology: DDR5 SDRAM
• Capacity: 16GB single module
• Speed Rating: PC5-38400
• Latency: CL40 for balanced performance
• Data Integrity: ECC with registered design
• Rank Configuration: 1Rx8

Packaging and Shipping

Each module is securely packaged to prevent damage during shipping. With lightweight construction (0.20 lbs), the Samsung DDR5 Registered DIMM is compact yet durable, ensuring safe handling and easy installation.

 Advantages of Samsung DDR5 Module

• Reliable ECC-registered module for enterprise-class computing
• Cutting-edge DDR5 speed and performance
• Samsung’s proven track record in memory technology
• Optimized for data centers, servers, and professional workstations
• Future-proof upgrade path with DDR5 standardization

Overview of Samsung M321R2GA3BB0-CQKMG 16GB DDR5 RAM 

The Samsung M321R2GA3BB0-CQKMG is a 16GB DDR5 RDIMM (Registered DIMM) designed for enterprise servers and professional workstations that require ECC (Error-Correcting Code) reliability and high, stable bandwidth. Rated at PC5-38400, this module delivers a peak transfer rate of DDR5-4800 MT/s, aligning with JEDEC standards for next-generation data center memory. As a registered ECC module, it is engineered for multi-channel server platforms, enabling greater memory density, lower electrical loading on the memory controller, and dependable 24/7 operation in virtualization, HPC, AI inference, database, and storage workloads.

This category page explores the features, benefits, compatibility considerations, and deployment scenarios for Samsung’s 16GB RDIMM DDR5 solution. It clarifies key differences between UDIMM vs RDIMM vs LRDIMM, outlines best practices for installation across Intel Xeon and AMD EPYC platforms, and provides troubleshooting, optimization, and lifecycle guidance for IT managers and system integrators building resilient infrastructure at scale.

Key Specifications and Technical Highlights

While individual server vendors may publish slightly different qualified part lists, the core characteristics of the Samsung M321R2GA3BB0-CQKMG 16GB module generally include the following industry-aligned attributes:

• Capacity: 16GB per module (ideal for balanced population across channels).
• Memory Type: DDR5 RDIMM (Registered DIMM) with on-DIMM PMIC and ECC.
• Speed Grade: PC5-38400 (DDR5-4800 MT/s), JEDEC-compliant.
• Form Factor: 288-pin DIMM, keyed for server/workstation boards supporting DDR5 RDIMM.
• ECC: Yes. On-die ECC plus system-level ECC for enhanced data integrity.
• Buffering: Registered (includes a register/clock driver for signal integrity at scale).
• Voltage: DDR5 standard operating voltages (e.g., VDD ≈ 1.1V; VPP ≈ 1.8V; managed by on-module PMIC).
• Thermal Sensors: On-DIMM temperature monitoring for platform-level thermal management.
• Rank/Organization: Typically available in 1Rx8 or 2Rx8 organizations; consult your server QVL or the module label to confirm the exact rank for your batch.
• Use Case: Enterprise servers, virtualization clusters, cloud nodes, professional workstations requiring registered ECC memory.

In practical deployments, DDR5 RDIMMs like this Samsung 16GB module complement modern multi-channel architectures, allowing administrators to scale memory bandwidth and capacity predictably while preserving signal integrity and uptime.

Understanding PC5-38400 (DDR5-4800) Performance

The PC5-38400 nomenclature corresponds to a theoretical bandwidth of 38.4 GB/s per module. That throughput stems from the DDR5-4800 MT/s transfer rate, which doubles data transfer on each clock cycle compared to single data-rate designs. The DDR5 standard also splits each DIMM into two 32-bit sub-channels (plus ECC bits), improving parallelism, reducing latency in certain access patterns, and enhancing overall efficiency for multi-threaded server workloads.

When populated across the memory channels of an Intel Xeon or AMD EPYC platform, even modest configurations (e.g., 8×16GB per CPU) can provide substantial aggregate bandwidth, helping databases flush logs quickly, letting hypervisors schedule memory-intensive VMs smoothly, and enabling data pipelines to keep pace with multi-core CPU throughput. Consistency and predictability of service are often as important as headline speed; registered ECC modules like M321R2GA3BB0-CQKMG are optimized for exactly that.

ECC and Registered Architecture 

ECC (Error-Correcting Code) memory detects and corrects single-bit errors and detects (and flags) many multi-bit errors before they impact the operating system or applications. Over long uptimes and large memory footprints, ECC reduces the probability of silent data corruption, kernel panics, and application crashes.

Meanwhile, the Registered design—sometimes described as “buffered”—places a register between the memory controller and the DRAM chips. This reduces the electrical load seen by the memory controller, enabling higher capacity per channel and more DIMMs per channel (DPC) than unbuffered modules. The combination of ECC + Register is a cornerstone of server reliability and scalability, especially in nodes with high memory density.

Typical Compatibility Scenarios

The Samsung M321R2GA3BB0-CQKMG 16GB RDIMM is designed for platforms that specifically list DDR5 RDIMM ECC in their specifications. Common environments include:

• Server Motherboards: Boards based on enterprise chipsets supporting DDR5 RDIMM (e.g., platforms for modern Intel Xeon Scalable or AMD EPYC processors).
• Workstations: Some professional workstation boards accept DDR5 RDIMM ECC; verify the vendor’s QVL (Qualified Vendor List).
• Not for Desktops: Consumer motherboards that use DDR5 UDIMM are not compatible with RDIMMs. Always check the memory type.

Before purchase or deployment, confirm the following:

• Whether the target platform requires RDIMM or LRDIMM—do not mix types within a channel.
• Supported speeds at specific DIMMs-per-channel (DPC) configurations; some platforms downclock with higher DPC.
• Rank mixing rules—many servers allow mixing 1R and 2R modules per channel but may optimize best with uniform ranks.
• Firmware/BIOS levels—ensure you have the recommended version for DDR5 stability and compatibility.

RDIMM vs UDIMM vs LRDIMM

RDIMM: Balanced Capacity and Stability

RDIMM, the category for the M321R2GA3BB0-CQKMG module, offers a strong balance of capacity, throughput, and cost. The register helps maintain signal integrity as you add modules per channel, enabling multi-socket servers to reach high total memory footprints without overwhelming the memory controller.

UDIMM: For Consumer Desktops

Unbuffered DIMMs (UDIMMs) are designed for consumer and some entry-level workstation boards, prioritizing latency and cost over extreme scalability. They lack the register and typically are not ECC-enabled in consumer ecosystems. UDIMMs are not compatible with server boards that mandate RDIMMs.

LRDIMM: Higher Density with Load Reduction

Load-Reduced DIMMs (LRDIMMs) include an isolation buffer that further reduces electrical load, enabling even higher capacities per channel than RDIMMs at the cost of additional latency and higher price points. Some data center deployments that chase maximum capacity (e.g., large in-memory databases) prefer LRDIMMs; however, the 16GB capacity point here is well matched to RDIMM economics and performance.

Ideal Use Cases for Samsung 16GB DDR5 RDIMM ECC

• Virtualization Hosts: Populate multiple 16GB modules per CPU to give hypervisors predictable, balanced capacity with ECC safety.
• Containers and Microservices: Many small services benefit from fast, reliable memory; 16GB increments simplify right-sizing nodes.
• Databases & Caching: In-memory caches, OLTP systems, and analytics engines benefit from consistent DDR5 bandwidth and ECC.
• Software Build Farms & CI: High parallelism and large codebases see smoother performance with ample reliable RAM.
• Edge & Branch Servers: ECC reduces risk in remote deployments where downtime is costly and access is limited.
• NAS/SAN Controllers: Storage nodes and metadata servers value integrity and uptime; registered ECC is standard practice.
• Professional Workstations: CAD, EDA, media finishing, and scientific modeling benefit from ECC stability during long renders.

Capacity Planning Strategies with 16GB Increments

Using 16GB modules simplifies balanced population across channels. For example, if your CPU supports eight channels and you employ one DIMM per channel, a baseline of 8 × 16GB = 128GB per CPU provides excellent bandwidth utilization without complex rank mixing. Two DIMMs per channel would bring that to 256GB per CPU, subject to platform-specific speed adjustments at higher DPC counts.

IT teams often choose 16GB RDIMMs to maintain flexibility: you can scale nodes gradually and repurpose modules across clusters with minimal stranded capacity. This granular approach also eases inventory management, as spares are interchangeable between many systems.

Latency, Timings, and Real-World Throughput

DDR5’s architectural improvements—sub-channels, improved burst length, on-die ECC, and onboard PMIC for tighter voltage regulation—tend to improve effective throughput and QoS, especially under mixed random and sequential memory access patterns typical in servers. While enthusiasts often focus on CAS latency numbers, the total performance picture in server workloads depends more on multi-channel bandwidth, NUMA topology, rank interleaving, and the predictability of service under load. The M321R2GA3BB0-CQKMG’s JEDEC-compliant DDR5-4800 profile provides the consistent baseline many enterprises require.

Reliability and Data Integrity Benefits

• On-die ECC (ODECC): Internal correction within each DRAM die for improved yield and stability.
• System-level ECC: Detects and corrects single-bit errors in data moving between the CPU and memory.
• Registered Buffering: Reduces electrical stress on the memory controller, improving stability at scale.
• Thermal Telemetry: On-DIMM sensors facilitate dynamic fan curves and thermal throttling, preserving longevity.
• Server-class PCB: Multi-layer routing and impedance control for clean signal paths at high data rates.

Tuning for Workload Performance

NUMA Awareness

On multi-socket platforms, bind memory-intensive processes to the local NUMA node when feasible. This reduces cross-socket traffic and improves latency. Align VM vCPU and vRAM allocations to the same socket whenever possible.

Interleaving and Ranks

Balanced populations that enable channel, bank, and rank interleaving typically yield smoother performance. When choosing between 1R and 2R modules, note that 2R may increase parallelism but can influence platform-specific speed behavior at higher DPC.

Thermal Headroom

Ensure adequate airflow across the DIMM banks. DDR5’s on-module PMIC benefits from steady cooling. Monitor DIMM temperatures through IPMI/BMC tools and adjust fan policy to keep modules within recommended ranges under sustained load.

Power Efficiency and the DDR5 PMIC Advantage

DDR5 introduces an on-DIMM PMIC (Power Management IC), moving power regulation closer to the DRAM dies for improved granularity and efficiency. The result is tighter tolerances, fewer transient dips, and more reliable operation at high speeds. For data centers, this can translate into better performance-per-watt and more consistent service levels during traffic spikes.

Server Architecture Notes for DDR5 RDIMM

Modern server CPUs feature multiple independent memory controllers, each with several channels. DDR5’s dual sub-channel design per DIMM increases concurrent operations and improves read/write turnarounds. To exploit this, populate channels evenly and avoid stranded channels on one socket when the other is fully populated. For dual-socket boards, keep populations symmetrical on both sockets to balance NUMA domains.

Samsung for Enterprise Memory

Samsung is one of the world’s largest DRAM manufacturers, with deep vertical integration from wafer to module. For enterprise buyers, that translates into predictable supply, proven quality control, and a robust validation ecosystem with server OEMs and motherboard vendors. The M321R2GA3BB0-CQKMG part number reflects Samsung’s internal coding for a 16GB DDR5 RDIMM, aligning with the company’s broader DDR5 portfolio and roadmap.

Pairing with Storage 

Memory performance rarely exists in isolation. Fast NVMe storage and high-bandwidth networking (25/40/100/200GbE, or InfiniBand) rely on the CPU’s ability to stage data quickly in RAM. The Samsung 16GB PC5-38400 RDIMM offers consistent throughput for DMA operations, packet processing, and page cache, keeping I/O stacks saturated without inducing latency spikes that can cascade through microservices and distributed databases.

Planning a Mixed-Capacity Environment

Some clusters will combine 16GB RDIMMs with larger capacities (e.g., 32GB, 64GB) as needs evolve. Follow these guidelines:

• Within a channel, use matched capacities and ranks for optimal interleaving.
• If mixing by socket, mirror the population on the second socket for symmetry.
• Document which nodes carry which capacity so your scheduler can place memory-hungry workloads appropriately.

Workstation Considerations

Certain professional workstation platforms accept DDR5 RDIMM ECC. For CAD, simulation, and color-critical media work, ECC protects long renders and iterative solves from bit errors. If your board supports RDIMM, the Samsung 16GB PC5-38400 module is a dependable building block that scales smoothly to higher capacities while keeping latency consistent across channels.

Best Practices for Inventory and Asset Management

• Barcoding: Affix or scan barcodes during intake; associate each DIMM to a device and slot in your CMDB.
• Lifecycle Tags: Track install date to align with refresh cycles and warranty windows.
• RMA Readiness: Keep packaging and documentation for streamlined returns if a failure occurs.
• Sparing Policy: For mission-critical racks, keep hot spares in the same row to minimize MTR (Mean Time to Repair).

Scalability Scenarios with 16GB Modules

Start with one DIMM per channel to unlock full data rate and low contention, then scale to two DIMMs per channel for capacity growth. For example:

• 8-Channel CPU, 1 DPC: 8 × 16GB = 128GB baseline; excellent for mid-tier virtualization hosts.
• 8-Channel CPU, 2 DPC: 16 × 16GB = 256GB per CPU; evaluate downclock behavior and thermals.
• Dual-Socket, 1 DPC each: 256GB total; scale cores and NICs to match memory bandwidth.

Interoperability with OEM Systems

Many server OEMs qualify broad sets of third-party modules. While the Samsung M321R2GA3BB0-CQKMG adheres to JEDEC DDR5 RDIMM standards, always verify whether your OEM requires vendor-specific FRU part numbers or firmware for hot-swap serviceability and warranty alignment. In mixed fleets, maintain a mapping between OEM FRUs and this Samsung part to streamline spares.

Testing Methodology Suggestions

When validating the Samsung 16GB RDIMM in your environment:

• Use sustained memory stress tools for at least several hours under production-like cooling.
• Exercise both sockets in dual-socket configurations to observe cross-socket behavior.
• Profile bandwidth with synthetic tests and then corroborate with real application traces.
• Record idle and loaded DIMM temperatures, fan speeds, and ECC counters.

Documentation and Label Decoding

Samsung module labels typically reveal speed grade, ranks, and manufacturing data. For the M321R2GA3BB0-CQKMG, look for printed indicators such as 1Rx8 or 2Rx8, the DDR5 speed (4800), and ECC/RDIMM markings. Keeping a photographic record of labels in your CMDB simplifies future audits and RMA handling.

Return on Investment Considerations

The 16GB capacity point often hits a sweet spot: it’s affordable, plentiful, and easy to balance across channels. Compared to jumping straight to higher-capacity DIMMs, using more 16GB modules early can yield more channels active at top speed, enhancing bandwidth per dollar. As needs grow, you can redeploy 16GB modules to edge or development nodes while upgrading core nodes to larger capacities—maximizing hardware reuse.

Safety, Compliance, and Handling

Store modules in anti-static packaging in a dry, temperature-controlled environment. Avoid stacking without protective trays. Follow your organization’s ESD policy during transport and installation. Compliance with regional environmental directives (e.g., RoHS) is standard for enterprise modules; retain datasheets and compliance statements for audit purposes.

Consider Larger Capacities

If telemetry shows frequent swapping, GC pauses due to memory pressure, or database buffer cache misses beyond your SLOs, consider moving up to 32GB or 64GB RDIMMs. Still, many mixed environments continue to use 16GB modules for less demanding nodes, staging, CI/CD, and batch processing workers where reliability matters more than maximum per-node RAM.

Glossary

ECC (Error-Correcting Code)

A mechanism that detects and corrects memory bit errors to prevent data corruption and crashes.

RDIMM (Registered DIMM)

A server-class DIMM with a register/buffer that reduces electrical load on the memory controller, enabling higher capacities and stability.

LRDIMM (Load-Reduced DIMM)

A DIMM type with an isolation buffer for even greater load reduction, allowing very high capacities.

JEDEC

The standards body that defines electrical and performance specifications for memory modules like DDR5.

PMIC

Power Management IC; on DDR5 DIMMs, it manages local power regulation for stability and efficiency.

PC5-38400 / DDR5-4800

Speed/bandwidth designation indicating 4800 MT/s data rate and approximately 38.4 GB/s theoretical bandwidth per DIMM.