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Green rectangular DDR4 server memory module with gold contacts and black chips

A-Tech

A-Tech 64GB DDR4 2666MHz ECC RDIMM 4Rx4 Server Memory

SKU CH-MJT7-4TZ38

64GB DDR4 2666MHz ECC registered server module with 4Rx4 organisation, CL19 latency and 1.2V operation

  • Capacity64GB
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.20V
  • ECCYes
  • Buffered/RegisteredRegistered
  • 64 GB capacity lets servers handle larger workloads
  • DDR4 2666 MHz speed moves data at PC4-21300 rates
  • ECC RDIMM design corrects errors for stable operation
  • Registered 4Rx4 organisation supports high-density configurations
  • 2 V DDR4 voltage reduces power draw per module

Capacity and purpose

This 64 GB DDR4 module is a registered ECC DIMM built for server and workstation systems that require error-correcting memory. It replaces the Cisco UCS-MR-X64G4RS-H and 15-105083-01 part numbers for direct compatibility. Buyers who need unbuffered UDIMMs or non-ECC memory for desktop platforms cannot use this module.

Thermals and power

Operating at the standard DDR4 voltage of 1.20 V, the module runs within normal power envelopes for registered server memory. The registered buffer adds a clock cycle of latency but reduces electrical load on the memory controller, helping stability in densely populated slots. No active cooling is included or required beyond typical server chassis airflow.

Build and connectors

The stick uses a 288-pin DIMM form factor with a 4Rx4 rank organisation and CL19 timing at 2666 MHz. Major-brand DRAM chips are used and every unit undergoes quality-assurance testing before shipment. Systems that cannot address 4Rx4 registered DIMMs or that lack DDR4 RDIMM slots will not accept this upgrade.

Highlights

  • 64 GB capacity lets servers handle larger workloads
  • DDR4 2666 MHz speed moves data at PC4-21300 rates
  • ECC RDIMM design corrects errors for stable operation
  • Registered 4Rx4 organisation supports high-density configurations
  • 2 V DDR4 voltage reduces power draw per module

Specifications

BrandA-Tech
SeriesCompatible Replacement for Cisco
ModelUCS-MR-X64G4RS-H, 15-105083-01
Capacity64GB
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.20V
ECCYes
Buffered/RegisteredRegistered
Rank2S2Rx4 (4Rx4)
ChipsetMajor Brand Chipset
FeaturesUCS-MR-X64G4RS-H, 15-105083-01

Questions about this item

How do I install the 288-pin DDR4 DIMM and which notch alignment step is often missed?

Align the single key notch on the 288-pin DDR4 DIMM with the slot ridge, press straight down until both side clips click, and verify the module sits flush — the notch offset prevents backward insertion but first-time builders sometimes force it without checking orientation.

What maintenance or replacement will the 64GB ECC RDIMM need over its service life?

The module has no moving parts or user-serviceable components; ECC corrects single-bit errors on the fly, and the only replacement trigger is an uncorrectable multi-bit failure reported by the server’s memory health logs.

At what point does the 1.2V 2666MHz 4Rx4 registered design hit its thermal or electrical limit under sustained load?

The JEDEC-rated 1.20V operating voltage and registered buffer keep signal integrity within spec up to the rated 2666MHz; the first practical limit is the server’s DIMM-slot airflow capacity, not the module itself.

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