M321R4GA0BB0-CQKDS Samsung 32GB DDR5 SDRAM 4800MHz 288P RDIMM PC5-38400 ECC REG RAM

Samsung M321R4GA0BB0-CQKDS 32GB DDR5 RDIMM Memory Module Details

Overview of the 32GB DDR5 RDIMM (PC5-38400)

The Samsung M321R4GA0BB0-CQKDS is a server-grade 32GB DDR5 Registered DIMM engineered for enterprise platforms that demand stability, error correction and sustained throughput. Built to the DDR5-4800 (PC5-38400) performance class, this module brings the standard DDR5 advances — higher data rate, improved power efficiency, and on-module features that help modern CPUs and chipsets extract predictable performance from memory subsystems. The part is commonly stocked and sold as an OEM Samsung RDIMM and is widely used across cloud, virtualization and database servers. 

These concise facts make the module a straightforward candidate for mainstream server deployments where single-module 32GB building blocks are common and predictable DIMM behavior is important for dense memory configurations.

Architecture & design highlights

DDR5 advantages built into the module

DDR5 introduced multiple architectural shifts versus DDR4 — internal bank groupings were expanded, on-die ECC for the DRAM chips is now common, and the command/address bus is improved to support higher frequencies. Samsung's M321R4GA0BB0-CQKDS leverages these enhancements to deliver higher sustained bandwidth at lower per-bit energy cost compared with earlier generations, while RDIMM registration helps present cleaner signals to the memory controller in multi-module configurations.

Registered buffering (RDIMM) — why it matters

The “R” in RDIMM denotes a register chip on the module that buffers command and address signals between the memory controller and the DRAM devices. This buffering reduces electrical loading as DIMM count increases, improving signal integrity and enabling the host platform to support higher DIMM population per channel — a crucial attribute for servers and large workstations. RDIMMs carry the tradeoff of slightly higher latency versus unbuffered parts, but in multi-DIMM, high-capacity server environments the stability benefits far outweigh that small penalty.

ECC (Error-Correcting Code)

ECC in registered server DIMMs like the M321R4GA0BB0-CQKDS provides multi-bit error mitigation, ensuring data integrity across frames of memory — a non-negotiable for transaction systems, telecom gear and analytics workloads. In practice this module implements ECC handling consistent with JEDEC DDR5 RDIMM conventions; the host platform (motherboard/BIOS/CPU) orchestrates ECC usage and error reporting.

Physical and electrical design

Physically the module conforms to the 288-pin DDR5 DIMM mechanical standard. Electrically it targets a 1.1V nominal supply and operates across JEDEC-specified VDD/VDDQ windows for DDR5. On many vendor listings the module is identified as CL40 (Column Address Strobe Latency 40) for DDR5-4800 — note that exact latency/secondary timing values can vary slightly between Samsung internal SKUs or later steppings; always confirm the exact timing on the product datasheet or retailer page before large-scale procurement.

Performance profile — what to expect

Bandwidth and throughput

At DDR5-4800 the theoretical peak transfer is captured by the PC5-38400 naming: ~38.4 GB/s per DIMM channel (dual-data-rate calculation varies by bus width and channel count). In real server workloads the effective gains are workload-dependent: memory-bandwidth bound tasks such as in-memory databases, analytics, compression, encryption, and certain AI preprocessing steps benefit the most. Conversely, pure single-threaded compute tasks may show modest improvements unless paired with multi-core concurrency or software optimized for higher memory throughput.

Latency considerations

DDR5 increases peak bandwidth but introduces slightly higher CAS latency figures compared with DDR4. The CL40 designation commonly found on this module points to that tradeoff. In practical terms, total application latency depends on many system-level factors: CPU memory controller design, interleaving, DIMM population, BIOS timings, and the nature of memory accesses. For throughput-centric server workloads, DDR5-4800’s superior bandwidth typically outweighs the single-access latency delta.

Real-world workload examples

• Virtualization & cloud hosts: More VMs per host with lower risk of memory-induced instability.
• Enterprise databases: Faster table scans and improved cache refresh rates when main-memory fits larger working sets.
• AI/ML preprocessing: Quicker data shuffling and feature extraction for batch pipelines.
• High-performance computing: Bandwidth-sensitive kernels (memory-bound matrix ops, FFTs) gain measurable improvements.

Compatibility & platform considerations

Server CPU families and chipset support

The M321R4GA0BB0-CQKDS is intended for modern server platforms that explicitly support DDR5 RDIMM modules at DDR5-4800 speeds. When planning upgrades or new builds, verify compatibility lists from server or motherboard vendors; many Intel Xeon (4th Gen onward) and AMD EPYC (Genoa onward) platforms introduced official DDR5 support, but each vendor and motherboard revision has its own validated DIMM lists and maximum supported DIMM densities per channel. Always consult the system vendor's Qualified Vendor List (QVL) or memory compatibility matrix prior to ordering at scale.

DIMM population and performance tuning

Memory topology (how many DIMMs per channel, ranks per DIMM, interleaving settings) affects both raw throughput and latency. Single-rank modules like 1Rx4 behave differently from dual-rank modules when the memory controller enables certain multi-channel optimizations. For peak throughput, follow the platform guidance for balanced population (for example, evenly populate channels across memory channels). BIOS settings such as memory speed selection (fixed vs. auto), gear-down mode, and XMP/JEDEC profile selection may be available on some server boards and can influence final operating frequency and timings.

Firmware and BIOS updates

Memory interoperability is often improved through firmware and BIOS updates. When deploying DDR5 RDIMMs, ensure your platform firmware is up-to-date — vendors frequently release microcode and BIOS revisions to expand DIMM compatibility lists and resolve timing/initialization edge cases.

Procurement, pricing & sourcing guidance

OEM vs. channel vs. refurbished options

You’ll commonly see three sourcing routes: OEM (factory-sealed Samsung modules), channel resellers (retailers and distributors), and refurbished/recertified sticks from secondary marketplaces. OEM modules typically include manufacturer traceability and sometimes warranty coverage, while certified channel partners offer bulk pricing and logistics. Refurbished sticks can be economical but carry higher risk — confirm seller reputation, return policies and individual stick testing details if you consider that option. Typical retailers and distributors list this SKU with part numbers closely matching Samsung's internal designation.

Cost-per-GB and TCO

DDR5 server modules currently command a premium compared to DDR4; however, the cost-per-performance for memory-bandwidth-bound workloads often justifies the investment. When calculating TCO, include factors like energy savings (DDR5’s lower voltage and better efficiency), consolidation benefits from increased VM density, and lower incident rates owing to ECC protection.

Comparison & alternatives

How the M321R4GA0BB0-CQKDS stacks up

When placed alongside other 32GB DDR5 RDIMMs, Samsung’s module competes on the foundation of vendor pedigree, wide distribution, and JEDEC compliance. Alternatives include equivalent-capacity RDIMMs from other major DRAM makers or server memory specialists. If your priority is raw cost, some channel brands sell compatible 32GB DDR5 RDIMMs at lower price points; if your priority is vendor-backed traceability or compatibility with Samsung-validated platforms, the Samsung OEM SKU is preferable.

Choosing between ranks and capacities

Single-rank (1R) modules like 1Rx4 are frequently recommended where maximum DIMM population and best channel balancing are needed; dual-rank modules may sometimes provide higher effective throughput under certain memory controller behaviors. Select rank/organization based on your platform’s documented best practices and performance testing.