General

Engineer's Note

This registered ECC DDR2-400 module is designed for legacy server platforms, delivering the reliability required for virtualization hosts and in-memory databases where data integrity is non-negotiable. The combination of registered signal buffering, ECC error correction, and a low CL3 latency in a single-rank x4 organization ensures stable, validated operation across fully populated memory channels while guarding against silent data corruption.

Technical Specs & Insights

1. ECC protection corrects single-bit memory errors autonomously, preserving data integrity for mission‑critical enterprise applications that cannot tolerate silent corruption.
2. Registered signal buffering stabilizes command and address lines under heavy DIMM populations, enabling dependable memory expansion in dense server racks.
3. Single Rank x4 organization balances electrical loading on the server memory channel, ensuring clean signal integrity and consistent boot‑level compatibility with older platforms.
4. The 1 GB capacity fits dedicated lightweight roles such as embedded hypervisors or legacy network appliances, where minimal overhead keeps total cost and power strictly controlled.
5. CL3 low‑latency access response reduces initial word fetch delay, benefiting latency‑sensitive transactional workloads that depend on rapid small‑block retrieval.

Why These Specs Matter

In server environments, the M393T2950CZP‑CCCQ0 RDIMM is engineered to eliminate the kind of silent errors and instability that directly threaten business continuity. Its ECC technology actively detects and corrects single-bit memory faults, a critical defense in virtualized clusters where a flipped bit in one guest can corrupt an entire application stack or trigger costly failover events. The registered signal buffer addresses a common pain point: as you populate multiple DIMMs to scale capacity, electrical loading increases, causing signal degradation and boot failures. Registered logic isolates the command and address bus, allowing dense, stable configurations that keep your hypervisor fully loaded with VMs. For latency-sensitive workloads like an in‑memory Redis database, the module’s CL3 column access strobe and Single Rank x4 organization deliver swift, predictable data access. The x4‑bit wide DRAM chips improve burst‑error resilience and facilitate effective bank interleaving, raising throughput for transactional queries. Together, these features mean fewer data integrity incidents, reduced unplanned downtime, and a responsive platform that sustains heavy consolidation without compromising service‑level agreements.

Endurance & Reliability

General Virtualization
A single 1GB RDIMM is wholly inadequate for modern hypervisors; even a minimal ESXi or Proxmox host demands at least 4–8GB. For lightweight lab virtualization, populate all available channels with eight identical M393T2950CZP modules to reach 8GB, enabling perhaps two to three tiny VMs. However, expect severe memory pressure, and never overcommit RAM on this DDR2-400 platform.

In-Memory Database
In-memory databases like Redis or Memcached require the entire working set to reside in RAM, making this 1GB module impractical for production. You would need at least 16 modules (16GB) across a dual-socket system just to cache a small dataset, but the slow 400MHz clock and high latency will cripple throughput. This hardware is obsolete for in-memory workloads; consider it only for educational tinkering with tiny datasets.

High-Performance Computing
HPC nodes typically demand 64GB to multiple terabytes of bandwidth-sensitive memory. Deploying these 1GB RDIMMs means filling every slot—often 16 or 24 DIMMs per node—merely to achieve 16–24GB, severely limiting problem sizes. The DDR2-400 interface provides just 3.2GB/s per channel, creating a massive bottleneck for memory-bound MPI or OpenMP applications, confining this configuration to legacy scientific code testing only.

Verified Compatibility

Rigorously tested for reliable performance in servers like Dell PowerEdge 2950, HP ProLiant DL380 G5, and IBM System x3650.

FAQ