HMCG78AGBRA185N Hynix 16GB DDR5 5600MHz PC5-44800 Registered Cl46 SDRAM 288-pin RDIMM RAM

Comprehensive Product Overview

The Hynix HMCG78AGBRA185N is a high-performance 16GB DDR5 5600MT/s PC5-44800 Registered SDRAM memory module built for modern server systems. With advanced features like ECC (Error-Correcting Code), high bus speed, and optimized latency, it ensures better stability, faster performance, and reliability for data-intensive workloads.

Understanding the Hynix HMCG78AGBRA185N 16GB DDR5 RDIMM

The Hynix HMCG78AGBRA185N is a single 16-gigabyte module of DDR5 SDRAM, configured for use in server environments. Its part number encodes its key specifications, signifying a product built with the precision and quality synonymous with the Hynix brand. This memory module is engineered to deliver a significant leap in performance and power efficiency over previous DDR4 generations, making it an ideal solution for next-generation server platforms from leading OEMs.

Core Product Specifications at a Glance

Memory Capacity

This module offers a substantial 16GB (Gigabytes) of memory capacity on a single stick. It is configured as a 1x16GB module, meaning it is a single, monolithic unit. The internal organization is 1 Rank by 8 (1Rx8), indicating a single rank of memory chips with an 8-bit wide data path per chip. This configuration is common and offers a excellent balance of performance, compatibility, and cost-effectiveness for server deployments.

Memory Technology: DDR5 SDRAM

DDR5 SDRAM (Double Data Rate 5 Synchronous Dynamic Random-Access Memory) is the fifth generation of DDR memory technology. It brings fundamental architectural improvements over DDR4, including higher base speeds, increased bandwidth, improved channel efficiency, and enhanced power management. For servers, this translates to faster data access for CPUs, reduced latency for concurrent operations, and the ability to handle more virtual machines and demanding workloads simultaneously.

Data Transfer Rate and Bandwidth

The module operates at a data rate of 5600 MT/s (Mega Transfers per second). This is often colloquially referred to as its speed. In terms of industry-standard classification, this speed corresponds to a PC5-44800 rating. The "PC5" denotes a DDR5 module, and the "44800" indicates the theoretical peak bandwidth in megabytes per second (MB/s) for the module. Specifically, 5600 MT/s * 8 bytes = 44800 MB/s. This high bandwidth is crucial for preventing data bottlenecks between the memory and the processor in server applications.

RDIMM Form Factor

The Hynix HMCG78AGBRA185N is an RDIMM (Registered DIMM). Unlike unbuffered modules used in desktops, RDIMMs incorporate a register, or buffer, located 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 servers to support a much higher number of memory modules per channel and significantly larger total memory capacities while maintaining signal integrity and system stability. This is a non-negotiable feature for multi-socket servers and large-scale memory configurations.

Power Efficiency

Operating at a low 1.1 volts, this DDR5 module is more power-efficient than its DDR4 predecessors, which typically ran at 1.2 volts. This reduction in voltage directly translates to lower power consumption and reduced heat output. In a data center with thousands of servers, even a small saving per module aggregates into substantial operational cost savings and a reduced carbon footprint, while also easing thermal management challenges.

CAS Latency and Timings

The module features a CAS Latency (CL) of 46. CAS Latency is the number of clock cycles between a read command and the moment data is available. While a lower number is generally faster, in server RDIMMs, other factors like stability, capacity, and raw bandwidth often take precedence over ultra-low latency. The CL46 timing at 5600MT/s is a standard and robust timing for server-grade DDR5 memory, ensuring reliable performance.

Physical Interface: 288-Pin Design

The module utilizes a 288-pin edge connector, which is the standard physical interface for DDR5 DIMMs. It is mechanically different from the 288-pin design of DDR4 modules, featuring a slightly different notch key position to prevent accidental insertion into an incompatible motherboard slot. Ensuring physical compatibility is the first step in any server memory upgrade or build.

Deep Dive into DDR5 Server Advantages

The transition to DDR5 technology in the server space is not incremental; it is transformative. The Hynix HMCG78AGBRA185N leverages several key DDR5 innovations to deliver a superior server memory experience.

Dual Sub-Channel Architecture

While DDR4 operated with a single 64-bit data channel per DIMM, DDR5 splits this into two independent 32-bit sub-channels. This architectural shift allows for more efficient data handling, as the memory controller can issue separate commands to each sub-channel, effectively increasing concurrency and reducing command/address bottlenecks. This leads to greater overall efficiency and higher effective bandwidth for the server's CPU.

On-Die ECC (Error Correction Code)

A cornerstone of server memory reliability is error correction. DDR5 introduces On-Die ECC, a feature where each individual DRAM chip on the module has its own internal error correction circuitry. This allows the chip to detect and correct bit errors within itself before they are sent to the memory controller. This proactive correction at the source significantly improves data integrity and reliability, handling the smaller, more volatile memory cells inherent in advanced manufacturing processes.

Applications and Use Cases

The Hynix HMCG78AGBRA185N 16GB DDR5 RDIMM is purpose-built for a wide array of demanding server workloads where performance, capacity, and reliability are paramount.

Enterprise Servers and Data Centers

This module is a perfect fit for general-purpose enterprise servers running business-critical applications, databases (SQL, NoSQL), and file servers. The high bandwidth and reliability ensure smooth operation and quick response times for user requests and data transactions.

Virtualization and Cloud Infrastructure

In virtualized environments using hypervisors like VMware vSphere, Microsoft Hyper-V, or Proxmox, physical memory is a shared resource among multiple virtual machines (VMs). The high density and bandwidth of this 16GB DDR5 module allow for a greater VM density per host, improving server consolidation ratios and maximizing the return on hardware investment for private and public cloud deployments.

High-Performance Computing (HPC)

Computational tasks such as scientific simulations, financial modeling, and AI/ML training require massive data sets to be rapidly accessible by the CPU. The 5600MT/s bandwidth of this Hynix memory accelerates these data feeds, reducing computation time and increasing overall research and development throughput.

Compatibility

Ensuring compatibility is crucial when selecting server memory. The Hynix HMCG78AGBRA185N is designed for servers that support DDR5 technology and the RDIMM form factor.

Server Platforms

This memory module is intended for use with server platforms based on modern server CPUs that have integrated DDR5 memory controllers. This includes next-generation Intel Xeon Scalable Processors (e.g., Sapphire Rapids and Emerald Rapids) and AMD EPYC processors (e.g., Genoa and Bergamo). It is imperative to consult the server manufacturer's official memory compatibility list or qualified vendor list (QVL) to confirm that this specific Hynix module, or one with identical specifications, has been tested and validated for a particular server model.