AD390131 Dell 128GB DDR5 6400mt/s Pc5-51200 Registered 1.1v Cl52 DDR5 SDRAM 288-pin Rdimm RAM Module For Server

Overview of the 128GB DDR5 RDIMM Memory Module

The Dell AD390131 128GB DDR5 RDIMM offers advanced performance, speed, and reliability for enterprise-grade computing. Designed to deliver seamless data processing and greater efficiency, this registered memory module is purpose-built for Dell PowerEdge servers and other compatible systems, ensuring exceptional scalability for demanding workloads.

Main Information of Dell AD390131 128GB DDR5 RAM

• Brand: Dell
• Part Number: AD390131 
• Product Type: 128GB DDR5 SDRAM Memory Module

Technical attributes

• Capacity: 128 GB (single module)
• Memory standard: DDR5-6400 / PC5-51200
• Form factor: 288-pin RDIMM
• Rank & organization: Dual-rank (2Rx4)
• Error checking: ECC (Error-Correcting Code)
• Voltage: 1.10 V
• CAS latency: CL52
• Designed for: Rack and enterprise servers (OEM Dell qualification)

Optimized Server Compatibility

• Dell PowerEdge R670
• Dell PowerEdge R770
• Dell PowerEdge R6715
• Dell PowerEdge R6725
• Dell PowerEdge R7715
• Dell PowerEdge R7725

Dell AD390131 128GB DDR5 RDIMM RAM

The Dell AD390131 128GB DDR5 registered memory module is a high-density RDIMM designed for modern rack and tower servers, delivering a combination of capacity, ECC reliability, and the higher throughput of DDR5-6400 (PC5-51200). This DIMM is commonly sold as a single 128GB RDIMM, implements ECC and registered signaling for enterprise-class error detection and signal stability, and is specified as a dual-rank x4 (2Rx4) device with CL52 timing at 1.10V operating voltage — optimized for server workloads that require large memory pools and predictable latency. :contentReference[oaicite:0]{index=0}

Dell 128GB DDR5 RDIMM like AD390131 for servers

Enterprise environments increasingly demand both capacity and bandwidth. The AD390131 offers a pragmatic balance: the 128GB module increases system memory without needing many DIMM slots, while DDR5-6400 frequency provides substantially higher sustained bandwidth than earlier DDR4 modules. For virtualization, large in-memory databases, AI/ML inference caching layers, or dense container workloads, using high-capacity RDIMMs simplifies memory subsystem design and reduces the number of modules required per system, which can also help with thermal and electrical layout in multi-socket servers.

Benefits for specific use cases

Virtualization and hyperconverged infrastructure

Large virtual machine (VM) hosts benefit from 128GB DIMMs because they reduce the total number of required modules while enabling higher per-host memory ceilings. Consolidating memory on fewer, larger DIMMs can simplify inventory and lower slot contention when scaling VMs horizontally across hosts.

In-memory databases and analytics

Databases that perform in-memory caching or that keep working sets resident in RAM (e.g., Redis, Aerospike, Memcached, SAP HANA) gain from both the capacity and bandwidth of DDR5-6400. The higher MT/s increases throughput for sequential and random memory accesses, improving query response times under heavy concurrency.

Inference and feature stores

While training relies heavily on GPUs, inference servers and feature stores often need large CPU-side memory to hold models/feature tables. 128GB RDIMMs reduce the need for complex NUMA balancing across a high number of smaller DIMMs and provide a stable, ECC-protected pool for production inference workloads.

Technical deep dive

DDR5 introduced several architectural changes versus DDR4 (on-die ECC, improved channel architecture, power management, and higher device densities). The AD390131, as a DDR5 RDIMM, leverages these improvements and is optimized for 1.10V operation at DDR5-6400 speed. Dual-rank x4 organization balances rank count with signal integrity; the x4 bus width at each device level is an industry approach to balance density and reliability in high-capacity modules. CL52 reflects the CAS latency at the target frequency — while higher numerical latency appears larger than lower-speed modules, the net effect combined with the higher transfer rate yields lower effective access time per byte in many workloads.

Because this module is ECC and registered, the memory controller receives buffered, more stable signals and the DIMM itself can correct single-bit errors and detect multi-bit errors, increasing system resiliency in long-uptime server contexts. Registered modules also include address/command buffering, which helps signal integrity at high frequencies and high DIMM population counts.

Compatibility

Compatibility depends on the server make, model, BIOS/firmware revision, and the platform's memory topology. Dell typically publishes validated memory part numbers and compatibility matrices for its PowerEdge and enterprise platforms; AD390131 is an OEM-qualified Dell part and is listed as a supported 128GB DDR5 RDIMM option for many current generation Dell servers that accept 6400 MT/s RDIMMs. When planning an upgrade, confirm the server's maximum per-slot and overall platform memory capacity, the supported DDR5 speeds (some systems will downclock mixed DIMM populations), and any firmware updates required for large DIMM support.

Performance considerations and real-world expectations

Raw clock speed (MT/s) is only one factor. Effective memory performance depends on memory controller behavior, interleaving, NUMA placement, application access pattern, and system configuration. DDR5-6400 delivers more peak bandwidth per channel than DDR4 or lower-speed DDR5 modules, which benefits memory-bandwidth bound workloads (e.g., large analytics scans, streaming transforms, and certain ML inference tasks). However, single-thread latency may not improve proportionally; the net benefit in real applications is workload dependent.

Reliability, warranty, and sourcing considerations

Enterprise memory purchases should prioritize genuine OEM or fully warranted parts. AD390131 is sold through Dell channels and authorized resellers; using validated OEM memory reduces compatibility risk and ensures supportability with Dell’s server warranty (where applicable). Third-party or aftermarket modules can be cost-effective but may introduce support limitations and require additional verification testing. When buying, verify the seller’s warranty, return policy, and part provenance (new vs. refurbished vs. pulled modules). 

Comparisons: AD390131 vs alternative 128GB DDR5 RDIMMs

128GB DDR5 RDIMMs are available from multiple vendors and in different rank/organization choices (2Rx4 vs 4Rx4) and speeds (4800 / 5600 / 6400). The AD390131 as a 2Rx4 6400MT/s RDIMM offers higher bandwidth but make sure your server supports the 6400 speed; in some configurations, a 5600 or 4800 RDIMM may be more compatible or less expensive. The choice between 2Rx4 and 4Rx4 affects platform compatibility and maximum supported ranks per channel, which matters in high DIMM population systems. For the best fit, compare the server’s validated list: choose the highest speed and rank configuration supported without violating population/rank limits. 

Happens if my server doesn't boot after installing these DIMMs

If the server fails to boot, check these sequential steps: ensure modules are seated correctly, verify they are installed in the correct slots according to the server manual, reset BIOS to defaults, and update server firmware. If issues persist, try installing a single DIMM in the primary slot to validate the module and consult Dell support with diagnostic codes and the module serial number.

High-capacity RDIMMs typically run within standard server thermal envelopes, but dense configurations and high ambient temps can affect DIMM temperatures. Ensure adequate airflow, validate fan policies, and monitor thermal telemetry after installation. Some OEM modules include heat spreaders; enterprise chassis are usually designed with these thermal profiles in mind.

Additional Advantages

For final compatibility verification and technical specifications, consult Dell’s official memory upgrade pages and product listings that detail supported speeds, ranks, and server models. Reseller product pages and OEM spec sheets provide additional purchasing and part number information. When in doubt, Dell’s technical support and server documentation remain the authoritative sources for installation and compatibility guidance. 

Return on investment (ROI) considerations for data centers

Upgrading to high-capacity DDR5 modules can unlock denser virtualization, reduced node counts for the same memory capacity, and simplified inventory. While the initial cost per module is higher than lower capacity DIMMs, operational savings (fewer servers to manage, lower networking overhead for distributed workloads, and more efficient consolidation) often offset the hardware spend for medium and large deployments. Run a cost model that includes hardware, licensing (if per-socket), power, cooling, and management overhead to quantify ROI before large-scale rollouts.