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Four green DDR4 ECC UDIMM sticks in a kit

NEMIX RAM

NEMIX RAM 64GB (4x16GB) DDR4 2666 ECC UDIMM Synology RS3618xs

SKU CH-RFG4-YXN1W

64GB kit of four 16GB DDR4 2666 ECC UDIMM modules at 1.2V CL19 for Synology RS3618xs NAS

  • Total capacity64 GB (4 × 16 GB)
  • Rated speedDDR4 2666 (PC4 21300)
  • ChipsetMajor OEM Samsung, Micron, Hynix
  • CAS latencyCL19
  • Buffer typeUnbuffered
  • Rated voltage1.2 V
  • 64 GB total capacity for large NAS workloads
  • DDR4 2666 speed matches Synology RS3618xs specifications
  • ECC unbuffered design protects data integrity in RAID arrays
  • 2 V operation keeps power draw low
  • Four 16 GB modules fill all slots in a single kit

Synology RS3618xs memory kit

This 64GB kit contains four 16GB DDR4 2666 ECC UDIMM modules built for the Synology RackStation RS3618xs NAS. The unbuffered 288-pin DIMMs run at 1.20V with CL19 latency and a 2Rx8 rank structure. Major OEM chips from Samsung, Micron or Hynix are used throughout the kit.

ECC unbuffered UDIMM benefit

Error-correcting code detects and corrects single-bit errors to protect data integrity in the NAS. Unbuffered design keeps latency low for the RS3618xs memory controller. The four-module population fills all slots for maximum supported capacity in a single upgrade.

Verify NAS model and slot count

Confirm the unit is a Synology RS3618xs before ordering; other RackStation models may use different memory specifications. Ensure all four DIMM slots are free or that you are replacing the full existing set. Check the owner manual for the recommended installation sequence.

How it compares

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

Price $545.99
Typical for this category: the median of 21,161 items is $397.99.
Total capacity 64 GB (4 × 16 GB)
Higher than about 60% of the 20,941 comparable items (median 32 GB).
Price per GB $8.53 per GB
Typical for this category: the median of 20,941 items is $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 Unbuffered UDIMM
Part numberME21300-628K4
Total capacity64 GB (4 × 16 GB)
Product type288-Pin DDR4 ECC UDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Processor
ChipsetMajor OEM Samsung, Micron, Hynix
Memory
CAS latencyCL19
ECC supportYes
Buffer typeUnbuffered
Heat spreaderNo
Memory rank2Rx8
Power
Rated voltage1.2 V
Compatibility
Compatible systemsSynology
In the box
Included items64 GB (4 × 16 GB) DDR4 2666 MHz PC4-21300 2Rx8 1.2 V CL19 288-PIN ECC Unbuffered UDIMM KIT

Questions about this item

Will the 16 GB DDR4 modules need any firmware updates or re-seating after the Synology RS3618xs runs continuously for months?

No firmware is required for the modules; the 288-pin UDIMMs are designed for permanent installation and only need re-seating if the NAS is moved or serviced.

What limit appears first when the four 16 GB sticks run at 2666 MT/s CL19 under sustained heavy workloads?

The memory controller’s maximum supported speed of 2666 MT/s and the CL19 latency ceiling are reached before any thermal or power limit on the unbuffered ECC modules.

How much heat and power do the 1.20 V 2Rx8 ECC UDIMMs produce when the RS3618xs operates all day?

Each 16 GB module runs at 1.20 V with no heat spreader, so total kit power stays low and the NAS chassis fans handle the modest heat output.

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