604506-B21 HPE 8GB PC3-10600 1333MHz DDR3 RAM.

HPE DDR3 Server Memory Powering Legacy Enterprise Systems

The HPE 604506-B21 represents a specific category of enterprise-grade memory designed for reliability and performance in business-critical server environments. This 8GB DDR3 module operates at 1333MHz with ECC (Error Correcting Code) and registered technology, making it an essential component for maintaining system integrity in HPE ProLiant Gen8 and compatible server platforms.

Memory DDR3 Server Technology

DDR3 (Double Data Rate Type 3) memory represents the third generation of DDR SDRAM technology, offering significant improvements over previous generations in terms of bandwidth, power efficiency, and maximum memory capacity. While newer DDR4 and DDR5 technologies have emerged, DDR3 remains widely deployed in legacy enterprise systems that continue to deliver reliable service in data centers worldwide.

Capacity: 8GB

DDR3 vs. Previous Generations

Compared to DDR2 memory, DDR3 offers several key advantages: higher bandwidth capabilities (800-2133 MT/s vs. 400-1066 MT/s), lower operating voltage (1.5V vs. 1.8V), higher chip density, and improved prefetch architecture (8-bit vs. 4-bit). These improvements translate to better performance per watt and greater memory capacity potential within the same physical server footprint.

ECC and Registered Memory Enterprise Reliability

The HPE 604506-B21 incorporates two critical technologies that distinguish enterprise server memory from standard desktop memory: ECC (Error Correcting Code) and registered buffering. These features work in tandem to ensure data integrity and system stability in mission-critical computing environments where even single-bit errors can have catastrophic consequences.

Real-World ECC Benefits

In practical terms, ECC protection means that soft errors caused by cosmic radiation, electrical interference, or component aging won't compromise your business applications. For database servers, virtualization hosts, file servers, and other critical infrastructure, this protection is not just a luxury—it's a necessity for maintaining data integrity and system uptime.

Registered DDR3 Memory (RDIMM)

The "Reg" in the HPE 604506-B21 product description indicates that this is a Registered DIMM (RDIMM). Registered memory incorporates a register (or buffer) between the memory modules and the memory controller that handles electrical load reduction and signal integrity.

Registered vs. Unbuffered Memory

Unlike unbuffered memory (UDIMMs) that connect directly to the memory controller, RDIMMs use registers to buffer the command, address, and control signals between the memory controller and the DRAM chips. This buffering reduces the electrical load on the memory controller, enabling support for higher memory capacities and more memory modules per channel. While registered memory typically adds a small amount of latency (usually one clock cycle), this trade-off is acceptable in server environments where capacity and stability outweigh minimal latency concerns.

DRAM Chip Organization

The 8GB capacity is achieved through specific DRAM chip configurations, typically using 1Gb or 2Gb DRAM chips arranged in a dual-rank or quad-rank organization. The rank configuration affects how the memory controller accesses the DRAM chips and can impact the total number of modules supported in a system.

Speed and Timing Characteristics

The PC3-10600 designation corresponds to a module data rate of 1333 million second (MT/s), with a peak bandwidth of 10,600 MB/s. This speed represents a common operating frequency for DDR3 memory in enterprise servers, balancing performance with power consumption and compatibility.

Physical Dimensions and Connector

The module utilizes the standard 240-pin DDR3 DIMM form factor with a length of 133.35mm (5.25 inches) and height that conforms to server specifications. The key notch position differs from DDR2 and DDR4 modules, preventing accidental insertion into incompatible memory slots.

Thermal Considerations

While the HPE 604506-B21 typically does not include a heat spreader, the power consumption of approximately 3-4 watts per module is managed through server airflow design. In high-density configurations or environments with elevated ambient temperatures, proper chassis ventilation is essential to maintain optimal memory reliability and performance.

ProLiant Gen8 Server

HPE ProLiant Gen8 servers represent the primary platform for the 604506-B21 memory module. These systems include the DL380p Gen8, DL360p Gen8, DL380e Gen8, ML350p Gen8, and other Gen8 models. The intelligent provisioning and UEFI system firmware in Gen8 servers automatically detect and configure the memory parameters for optimal operation.

Memory Population Guidelines

HPE servers have specific requirements for memory population to ensure optimal performance and compatibility. These guidelines cover which memory slots to populate first, how to balance memory across processors, and maximum configuration limits.

Channel and DIMM Population Rules

Modern server architectures organize memory into channels, typically with three DIMM slots per channel. Proper population follows specific sequences to maximize memory performance and capacity. Most HPE servers require population starting with the white release tab slots, followed by the black tab slots, in a specific order depending on the number of processors installed.

Mixed Memory Considerations

While it's generally recommended to use identical memory modules throughout a server, mixed configurations may be supported with limitations. When mixing the HPE 604506-B21 with other modules, all memory will operate at the speed of the slowest module, and capacity organization should follow HPE guidelines to ensure stability.

Firmware 

Proper operation of the HPE 604506-B21 may require minimum system firmware levels. HPE Integrated Lights-Out (iLO) management controllers provide visibility into memory health and performance through the web interface and management software.

Reliability

Beyond raw performance, the ECC and registered features of the HPE 604506-B21 contribute significantly to system reliability and availability—critical factors for business-critical applications.

HPE Smart Memory Technology

Many HPE memory modules, including the 604506-B21, incorporate HPE Smart Memory technology, which provides additional features such as extended temperature range operation, enhanced system integration, and improved reliability characteristics compared to standard JEDEC modules.

Compatibility