A-Tech 16GB DDR4 2666 ECC RDIMM 1Rx4 Cisco UCS-MR-X16G1RS-H 15-105079-01 Server RAM

Capacity and Compatibility

This 16GB DDR4 2666 ECC RDIMM is a registered server memory module built for Cisco UCS systems matching part numbers UCS-MR-X16G1RS-H and 15-105079-01. It targets administrators upgrading compatible Cisco UCS servers or workstations that require registered ECC memory. Buyers needing unbuffered UDIMMs or non-ECC memory for consumer desktop platforms cannot use this module.

DDR4 2666 Registered Limits

The module operates at DDR4 2666 speed with a CAS latency of CL19 and runs at the standard 1.20V voltage for DDR4. As a registered DIMM, it places a lighter electrical load on the memory controller, which is necessary for the multi-DIMM-per-channel configurations common in servers. Systems that only accept unbuffered memory or that are limited to lower DDR4 speeds will not support this module at its rated specification.

Build and Connector Details

The stick uses a 288-pin DIMM form factor with a 1Rx4 rank organisation and major-brand chipset components. Registered ECC construction adds an on-board register and error-correction circuitry, which increases module height slightly compared to standard UDIMMs and requires motherboard slots wired for registered operation. The 262-pin notation in some references reflects the DDR4 DIMM edge-connector design; verify that your chassis and CPU cooler clearance accommodate the registered module height before installation.