M393AAG40M32-CAE Samsung 128GB DDR4 SDRAM 3200mhz PC4-25600 ECC RAM

Product Overview

The Samsung M393AAG40M32-CAE represents a pinnacle of reliability and performance in the realm of enterprise server memory. This specific 128GB module is engineered for mission-critical servers, data centers, and high-performance computing (HPC) environments where data integrity, large-scale data handling, and unwavering stability are non-negotiable. As a Registered (RDIMM), ECC, Quad Rank module operating at 3200Mbps, it is a cornerstone component for building robust, scalable, and powerful server systems.

Key Specifications

At its core, this module is a 128GB stick of DDR4 SDRAM, representing a pinnacle of density and technology for server platforms. It operates at a data transfer rate of 3200 megabits per second (Mbps) per pin, which corresponds to a module speed of PC4-25600. This speed ensures rapid data access and processing, reducing latency and improving overall system throughput for data-intensive applications.

Capacity: 128GB (1x128GB)

The "1x128GB" designation indicates a single module providing a massive 128 gigabytes of memory. This immense capacity per module allows data center architects and system administrators to build servers with terabyte-scale memory footprints using fewer DIMM slots. This maximizes memory per chassis, reduces power consumption per gigabyte, and simplifies system design and upgrades.

Decoding the Part Number: M393AAG40M32-CAE

The part number itself encodes key attributes: "M" for Memory Module, "393" for DRAM component type/organization, "A" for Revision, "AG" likely for 128GB density and RDIMM type, "40" for x4 component data width and rank, "M32" for 3200Mbps speed, and "C" for 1.2V. The suffix "AE" may indicate a specific revision or thermal characteristics. Always verify the exact part number required by your system.

Quad Rank (QR) Architecture

This module utilizes a Quad Rank (QR) design. A rank is an independent set of DRAM chips that is accessed simultaneously by the memory controller. Quad Rank modules pack four ranks onto a single stick, which is crucial for achieving such a high density (128GB). This architecture allows the memory controller to interleave operations across ranks, improving efficiency, though it requires careful population following the server motherboard's guidelines for optimal performance and compatibility.

Speed and Bandwidth: 3200Mbps & PC4-25600

The module's speed of 3200Mbps (often marketed as DDR4-3200) refers to its data rate. The "PC4-25600" is the module's naming convention, where "PC4" denotes DDR4 and "25600" represents the theoretical peak bandwidth in megabytes per second (MB/s). A single module can deliver up to 25.6 GB/s of bandwidth, calculated as (3200 Mbps * 8 bytes per transfer) / 8 bits per byte = 25,600 MB/s. This high bandwidth is essential for feeding modern multi-core CPUs with data.

CAS Latency and Timings: CL22

The CAS Latency (CL) of 22 cycles is a critical timing parameter. It indicates the number of clock cycles between the memory controller issuing a read command and the first piece of data being available. While higher CL numbers can suggest higher latency, in server memory, stability, capacity, and reliability are often prioritized over ultra-tight timings. The CL22 rating at 3200Mbps is a standard and optimized timing for high-density, high-reliancy server modules.

Advanced Reliability Features: ECC and Registered Design

This module incorporates two foundational server-grade technologies that distinguish it from standard desktop memory: Error-Correcting Code (ECC) and a Registered (Buffered) design.

Error-Correcting Code (ECC) Memory

ECC is a non-negotiable feature for enterprise servers. It detects and corrects the most common types of internal data corruption (single-bit errors) in real-time and can detect (though not correct) multi-bit errors. This prevents silent data corruption, system crashes, and computational errors that could lead to financial loss, data integrity issues, or service outages in a 24/7 operational environment. The Samsung M393AAG40M32-CAE includes advanced ECC functionality for maximum data integrity.

On-Die ECC (Optional Clarification)

Note: Some high-density Samsung modules also incorporate On-Die ECC, an additional layer of error correction within each DRAM chip itself, working in tandem with the standard module-level ECC. This further enhances reliability, especially vital for such a high-density component. Users should consult the official Samsung data sheet for this specific module to confirm the inclusion of this feature.

Registered (RDIMM) vs. Unbuffered Design

The "Registered" in RDIMM is key. A Registered DIMM includes a register (or buffer) on the module that sits between the memory controller and the DRAM chips. This register buffers the command and address signals, reducing the electrical load on the memory controller. This allows a server system to support a much larger number of memory modules (and thus, higher total capacity) while maintaining signal integrity and system stability. It introduces a one-clock-cycle delay but is essential for multi-socket servers and high-memory configurations.

Physical and Electrical Details

The module adheres to the standard form factor and electrical specifications for enterprise-grade DDR4 memory.

Form Factor: 288-Pin RDIMM

The module uses the standard 288-pin layout defined for DDR4 RDIMMs. The pin count and notch position are physically different from DDR3 or desktop UDIMMs to prevent accidental insertion into an incompatible slot. The RDIMM-specific pinout and the presence of the registering clock driver (RCD) chip are what define this form factor.

Module Height Considerations

High-capacity modules like the 128GB variant may sometimes use a slightly taller PCB ("Tall Height" or VLP+ profiles) or specialized components to accommodate the necessary DRAM chips. It is crucial to verify the module's exact dimensions (height) against the server manufacturer's compatibility list, especially in dense, blade, or 1U rack server environments where clearance is limited.

Operating Voltage: 1.2V

This DDR4 module operates at a standard voltage of 1.2 volts, a reduction from DDR3's 1.5V. This lower voltage translates directly into lower power consumption and reduced heat output per module, which is a critical factor when deploying dozens or hundreds of modules in a data center, impacting both operational electricity costs and cooling requirements.

Compatibility and Use Cases

The Samsung M393AAG40M32-CAE is not a generic memory component; it is designed for specific server platforms.

Server Platforms

This memory is intended for modern enterprise servers based on Intel Xeon Scalable processors (Cascade Lake, Ice Lake, and newer generations) or AMD EPYC 7002/7003 series (Rome, Milan) platforms and beyond. It is critical to consult the server's official memory compatibility list (e.g., Dell EMC's Quick Reference Guide, HPE's ProLiant Compatibility Matrix, or Supermicro's Memory List) to confirm support for this specific part number, density, rank, and speed. Not all servers that support DDR4-3200 will support a 128GB Quad Rank module.

Ideal Workloads and Applications

This high-density, high-reliability memory is purpose-built for the most demanding server applications. Primary use cases include: Large-scale virtualization hosts (VMware vSphere, Microsoft Hyper-V) requiring massive RAM pools to host hundreds of virtual machines. In-memory databases (SAP HANA, Oracle Database In-Memory, Microsoft SQL Server) where dataset size dictates the required RAM. High-Performance Computing (HPC) clusters performing complex simulations and modeling. Big Data analytics platforms (Apache Spark) that cache data in memory for rapid processing. Tier 1 cloud infrastructure and large-scale storage controllers.

Component and Module Integration

Samsung vertically integrates the production of this module, from the design and fabrication of the DRAM chips (the x4 organization indicates the data width of the individual chips) to the assembly and testing of the complete RDIMM. This end-to-end control allows for stringent quality assurance, optimal component matching, and firmware (SPD) programming tailored for stability.

Reliability

The module features a standard server green PCB. For optimal long-term performance in hot server environments, ensure the server's airflow design is adequate to cool these high-density modules. Some servers may recommend or require the use of specific airflow baffles or memory cooling options when populating all slots with high-capacity, high-speed DIMMs. The module's SPD contains thermal sensor data used by the server's management controller (BMC) for proactive monitoring.