64GB DDR4-2666 LRDIMM
Load-Reduced DIMM with on-module data buffers that isolate DRAM from the memory bus — delivering higher capacity per module, cleaner signal integrity and rock-solid stability for large-scale enterprise deployments.
Designed for High-Density Enterprise Memory
M386A8K40BM2-CTD is a Samsung 64GB DDR4 LRDIMM running at 2666MT/s (PC4-21300) with 1.2V low voltage, 4Rx4 quad rank and full ECC protection — built for capacity-hungry servers and workstations.
Capacity & organization. M386A8K40BM2-CTD is Samsung enterprise-grade DDR4 LRDIMM memory. Capacity is 64GB, speed DDR4-2666, CAS latency CL19, 288-pin standard server DIMM, operating voltage 1.2V, organization 4Rx4 quad rank with x4 DRAM structure.
How the part number reads. M386 indicates the LRDIMM type, A stands for the DDR4 generation, 8K represents 8Gbit DRAM density, 40 refers to x4 organization, BM2 is the die version and revision, and -CTD is the DDR4-2666 (PC4-21300) speed grade.
Why LRDIMM. Unlike standard RDIMM, LRDIMM integrates data buffers on the module. These buffers reduce the electrical load presented to the memory controller, allowing more ranks (up to 4R) and larger capacity per module while maintaining stable signal quality at high speed. ECC error correction automatically detects and repairs memory bit errors, significantly lowering crash risk under long-time heavy workloads.
Six Reasons to Standardize on It
Every module is engineered for the workloads that never sleep — virtualization, databases, analytics and AI.
High Capacity per Module
64GB in a single DIMM. The quad-rank 4Rx4 design maximizes memory density for memory-intensive platforms.
Better Signal Integrity
On-module data buffers isolate DRAM from the memory bus, reducing electrical loading and improving stability at DDR4-2666 speed.
ECC Error Correction
Detects and corrects single-bit memory errors automatically, protecting data integrity during 24/7 operation.
Low Power
1.2V operating voltage reduces platform power consumption and heat generation versus earlier DDR4 generations.
Enterprise Reliability
Samsung original-quality die with rigorous screening — stable in long-term, high-load server environments.
Wide Compatibility
Supports mainstream Intel and AMD server platforms with LRDIMM support — ideal for large-memory configurations.
Full Parameters at a Glance
Verified specifications for this exact part number. Always confirm compatibility with your server's Qualified Vendor List.
| Parameter | Specification |
|---|---|
| Brand | Samsung |
| Part Number | M386A8K40BM2-CTD |
| Module Type | DDR4 LRDIMM (Load-Reduced DIMM) |
| Capacity | 64GB |
| Speed | DDR4-2666 (PC4-21300) |
| CAS Latency | CL19 (19-19-19) |
| Organization | 4Rx4 (Quad Rank, x4 DRAM) |
| DRAM Density | 8Gbit |
| Error Correction | ECC (Error Correcting Code) |
| Pins | 288-pin |
| Voltage | 1.2V |
| PCB Height | Standard server DIMM (Low Profile on request) |
| Application | Server / Workstation (LRDIMM platforms only) |
Where 64GB per DIMM Pays Off
From virtualized fleets to in-memory analytics — built for workloads where capacity and reliability are the bottleneck.
Virtualization Platforms
VMware, KVM and Hyper-V hosts requiring large memory pools for many concurrent virtual machines.
Cloud & Hyper-Converged
High-density memory for scale-out data center nodes and hyper-converged infrastructure.
In-Memory Databases
SAP HANA, Redis and Memcached workloads that need maximum capacity per socket for resident datasets.
Big Data & Analytics
Hadoop, Spark and real-time analytics clusters with heavy per-node memory footprints.
HPC & AI
Scientific simulation and AI training nodes where memory bandwidth and capacity are critical.
Enterprise Applications
ERP and CRM systems that run 24/7 and demand ECC-protected memory for data integrity.
Before You Buy
Quick answers to the questions buyers ask most about LRDIMM memory.
LRDIMM adds data buffers on the module to isolate DRAM chips from the memory bus, reducing electrical loading. This allows higher capacity (e.g., 64GB 4Rx4) and more ranks per module with better signal integrity. RDIMM uses only a register for address/command signals without data buffering.
No. LRDIMM and RDIMM cannot be mixed on the same platform, and most servers require all memory slots to use the same module type. Check your server's memory configuration guide first.
It requires a server motherboard that supports DDR4 LRDIMM and 4Rx4 organization, such as mainstream Intel Xeon Scalable and AMD EPYC platforms with LRDIMM support. Always verify the Qualified Vendor List (QVL) of your motherboard or server vendor.
No. This is a 288-pin server LRDIMM with ECC and buffered design; standard desktop motherboards (UDIMM) are not compatible.
LRDIMM power consumption is generally similar to or slightly higher than RDIMM due to the data buffers, but the 1.2V low-voltage design keeps overall platform power efficient. Actual power depends on the number of modules and system load.
Quad-rank design allows more memory chips per module, achieving larger capacity (64GB) in a single DIMM. With LRDIMM data buffers, the extra ranks do not overload the memory controller, enabling high-density configurations that RDIMM cannot reliably support.
