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Green bare circuit board with black memory chips and gold edge connectors

NEMIX RAM

NEMIX RAM 64GB DDR4 2666 ECC RDIMM 4Rx4 CL19 1.2V 288-Pin Synology SA6400 memory upgrade

SKU CH-4EVY-W4613

64 GB DDR4 2666 ECC registered RDIMM validated for Synology SA6400 NAS expansion

  • Total capacity64 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • ChipsetMajor OEM Samsung, Micron, Hynix
  • CAS latencyCL19
  • Buffer typeRegistered
  • Rated voltage1.2 V
  • 64GB capacity expands Synology SA6400 NAS memory
  • ECC registered design protects data integrity under load
  • DDR4 2666 speed matches system specification
  • 2V operation reduces power draw and heat
  • 288-pin RDIMM form factor fits server motherboard slot

Synology SA6400 64GB DDR4 ECC RDIMM

This registered DDR4 module adds 64GB of ECC memory to a Synology SA6400 NAS. It targets administrators who need data integrity for file services, virtualization or backup workloads on that specific platform. The single-stick design leaves remaining slots free for future expansion. Buyers who want non-ECC memory or a different form factor cannot use this part.

Passive operation at 1.2V and CL19

The module runs at 1.2V with CAS latency 19 and no heat spreader, relying on chassis airflow for cooling. Registered buffering reduces electrical load on the memory controller, helping stability under sustained throughput. Power draw stays low because voltage and frequency are fixed at DDR4-2666. Systems without forced airflow over the DIMM slots may see higher temperatures.

288-pin 4Rx4 registered build

The 288-pin RDIMM uses a 4Rx4 organisation built from major OEM DRAM chips and fits only DDR4 RDIMM slots that support registered ECC. No heat spreader means a low profile that clears most CPU coolers, but the module must be seated in a compatible Synology SA6400 memory slot. Builders who need unbuffered UDIMMs or a different rank configuration cannot use this memory.

How it compares

Measured against everything we stock in Model-Specific Memory Upgrades, at today’s prices. Recalculated every night.

Price $273.99
Cheaper than about 55% of the 21,161 comparable items (median $397.99).
Total capacity 64 GB
Higher than about 60% of the 20,941 comparable items (median 32 GB).
Price per GB $4.28 per GB
Cheaper than about 83% of the 20,941 comparable items (median $8.19 per GB).

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Specifications

Product
Brand nameNEMIX RAM
Product lineSynology Compatible Series NAS Memory
Model nameSynology DDR4 2666 MHz ECC RDIMM Registered Server Memory
Part numberMR21300-944K1
Total capacity64 GB
Product type288-Pin DDR4 RDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Processor
ChipsetMajor OEM Samsung, Micron, Hynix
Memory
CAS latencyCL19
ECC supportYes
Buffer typeRegistered
Heat spreaderNo
Memory rank4Rx4
Power
Rated voltage1.2 V
Compatibility
Compatible systemsSynology
In the box
Included items64 GB (1 × 64 GB) DDR4 2666 MHz PC4-21300 4Rx4 1.2 V CL19 288-PIN ECC RDIMM Registered Server Memory

Questions about this item

How do I install this 288-pin DDR4 RDIMM into the Synology SA6400, and what step is often missed?

Power down the NAS, open the chassis, align the module notch with the slot key, press firmly until both side clips lock, then verify the SA6400 BIOS recognises the full 64GB capacity before closing the case.

What maintenance or replacement will this ECC registered module need over its service life?

No scheduled maintenance is required; the module either operates correctly or reports correctable errors via ECC, at which point the SA6400 management interface will flag the DIMM for replacement under lifetime warranty.

What limit appears first when this 4Rx4 CL19 kit runs sustained workloads on the SA6400?

The four-rank 4Rx4 organisation increases electrical loading on the memory controller, so the SA6400 chipset rank limit is reached before thermal or bandwidth ceilings become a factor.

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