4X77A93529 Lenovo 128GB DDR5 6400Mhz Pc5-51200 DDR5 SDRAM RAM Module for Server

Overview of the Lenovo 128GB DDR5-6400 Memory 

The Lenovo 4X77A93529 is a 128 GB DDR5 SDRAM Registered DIMM (RDIMM) engineered for high-density server configurations that demand exceptional bandwidth, predictable latency, and rock-solid reliability. Built for Lenovo ThinkSystem and other compatible DDR5 server architectures, this dual-rank x4 module combines 6400 MT/s transfer speed with ECC (Error-Correcting Code) and a 1.1 V operating profile to deliver faster data movement, improved power efficiency, and enhanced uptime for critical workloads.

Main Information

• Manufacturer: Lenovo
• Part Number: 4X77A93529
• Product Type: 128 GB DDR5 SDRAM RDIMM

Technical Features

• Data Rate: DDR5-6400 (PC5-51200)
• CAS Latency: CL52
• Rank/Org: 2Rx4 (dual rank, x4)
• Voltage: 1.1 V
• Pin Count: 288-pin
• ECC: Yes (Error-Correcting Code)
• Registered: Yes (Buffered)
• Quantity: 1 × 128 GB module

Key Details

• Capacity & Form Factor: 128 GB single module; 288-pin DDR5 RDIMM for server motherboards.
• Throughput Class: DDR5-6400 (PC5-51200) for substantial bandwidth headroom.
• Reliability: ECC with on-module parity to detect and correct common memory errors.
• Architecture: Dual Rank (2Rx4) layout optimized for concurrency and throughput.
• Latency: CL52 timing tuned for consistent response under load.
• Voltage: 1.1 V nominal for improved efficiency vs. previous generations.
• Server Focus: Registered (buffered) design for signal integrity on multi-DIMM channels.

Compatibility

The 4X77A93529 is tailored for Lenovo ThinkSystem platforms that support DDR5 RDIMMs. It integrates cleanly with validated server BIOS/UEFI profiles and memory topologies.

ThinkSystem Models

• ThinkSystem SR650 V2
• ThinkSystem SR630 V2
• ThinkSystem SR655 V3
• ThinkSystem SR645 V3
• Additional Lenovo DDR5-capable ThinkSystem servers as specified by Lenovo documentation

Note: Always consult the specific server’s Qualified Vendor List (QVL) or Lenovo documentation for population rules, maximum ranks per channel, and BIOS revisions that ensure optimal stability at 6400 MT/s.

DDR5 for Servers

DDR5 represents a fundamental leap in memory technology, enabling higher data rates, better power management, and improved reliability features compared with DDR4. For database engines, virtualization clusters, analytics pipelines, and application servers, DDR5-6400 modules like the 4X77A93529 accelerate memory-bound operations and create breathing room for CPU cores to execute more work per cycle.

Product Specification Deep Dive

Capacity & Configuration

This kit delivers 1 × 128 GB RDIMM, ideal for scaling capacity incrementally or standardizing on a high-density baseline. Dual rank (2Rx4) organization enables better interleaving and parallelism, helping sustain bandwidth and minimize stalls under mixed workloads.

Speed Class and Timing

Rated at DDR5-6400 (PC5-51200) with CL52, the module targets balanced performance where throughput and latency both matter. For write-heavy services, in-memory analytics, or fast caching layers, this speed class shortens memory queues and improves overall responsiveness.

ECC and Registered (Buffered) Design

ECC actively detects and corrects single-bit errors and identifies multi-bit anomalies, reducing the risk of data corruption and silent failures. The Registered buffer stabilizes command and address signals, allowing robust operation in servers populated with multiple DIMMs per channel.

Single-Socket Servers

For compact nodes and edge servers, a single 128 GB RDIMM provides ample headroom for microservices, web tiers, and branch analytics. Add DIMMs symmetrically according to the channel layout to preserve top speed.

Dual-Socket Systems

In mainstream 2P servers, pairing 128 GB modules across both CPUs allows rapid growth to 512 GB, 1 TB, or beyond while maintaining channel balance. Dual-rank modules often deliver favorable real-world throughput via interleaving.

Performance Considerations for PC5-51200

With a theoretical peak bandwidth of 51.2 GB/s per module, DDR5-6400 brings measurable gains to scan-heavy and memory-sensitive tasks. Real-world results depend on CPU generation, memory controller limits, DIMMs per channel, and BIOS memory training.

Latency vs. Bandwidth Balance

CL52 is designed to harmonize the latency curve with the high data rate. In practice, well-tuned servers see both improved sustained throughput and more predictable response times under mixed read/write pressure.

Scaling with Multiple DIMMs per Channel

While adding DIMMs increases capacity, some platforms may step down memory frequency when channels are heavily populated. Adhering to vendor population rules helps maintain higher speeds while achieving the desired memory footprint.

Reliability, Availability, and Serviceability (RAS)

Memory errors can cause application crashes or silent corruption. The 4X77A93529 mitigates these risks with ECC, parity, and a Registered design that reduces electrical loading on the memory controller. Together, these features strengthen uptime, especially in large configurations where error rates rise with density.

Use-Case

Virtualization Hosts

For hypervisors hosting large VM fleets, 128 GB RDIMMs reduce slot count while expanding per-node capacity. This can improve consolidation ratios and cut per-VM memory contention during peak hours.

Databases & Caching Layers

OLTP systems with heavy index activity and OLAP engines performing broad scans both benefit from high bandwidth and ample RAM. Large caches and buffer pools shorten disk waits, leading to lower query latency and higher transaction throughput.

Security and Data Integrity Considerations

ECC reduces exposure to data corruption by correcting bit errors in flight. For compliance-sensitive environments—finance, healthcare, government—this safeguards data integrity, minimizes unplanned downtime, and supports auditability through error logs and predictive failure alerts.