We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Sixteen green DDR4 RDIMM modules in a tray

NEMIX RAM

NEMIX RAM 256GB (16x16GB) DDR4 2666 ECC RDIMM Synology FS6400 memory upgrade

SKU CH-PWF7-PDV94

A 256 GB kit of sixteen 16 GB DDR4 2666 ECC registered DIMMs for Synology FS6400 NAS

  • Total capacity256 GB (16 × 16 GB)
  • Rated speedDDR4 2666 (PC4 21300)
  • ChipsetMajor OEM Samsung, Micron, Hynix
  • CAS latencyCL19
  • Buffer typeRegistered
  • Rated voltage1.2 V
  • 256GB total capacity across 16 matched modules for large NAS workloads
  • ECC registered design protects data integrity under continuous operation
  • DDR4 2666 speed with CL19 timing delivers responsive throughput
  • 2V operation reduces power draw in dense configurations
  • Validated for Synology FlashStation FS6400 compatibility out of the box

Synology FS6400 ECC RDIMM kit

This 256GB kit provides sixteen 16GB DDR4 2666 registered DIMMs built for the Synology FlashStation FS6400. ECC and registered buffering protect data integrity in a NAS that runs continuous file and backup workloads. The modules operate at 1.2V with a CL19 latency profile.

Sustained load behaviour

Registered buffering reduces electrical load on the memory controller so the FS6400 can keep all slots populated without signal degradation. ECC corrects single-bit errors on the fly during long replication or deduplication jobs. The 1Rx4 organisation maintains stable throughput across the full 256GB capacity.

Capacity and compatibility gate

The 256GB total across sixteen 288-pin slots is the decisive factor; the FS6400 must support this maximum population for the kit to function. Buyers whose NAS chassis or firmware limit memory to a lower ceiling cannot use the full kit.

How it compares

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

Price $1,501.99
Pricier than about 64% of the 21,161 comparable items (median $397.99).
Total capacity 256 GB (16 × 16 GB)
Higher than about 80% of the 20,941 comparable items (median 32 GB).
Price per GB $5.87 per GB
Cheaper than about 67% of the 20,941 comparable items (median $8.19 per GB).

New to this? Buying memory and SSDs with crypto — what to check, what it costs to pay, and what is never asked for.

Specifications

Product
Brand nameNEMIX RAM
Product lineSynology Compatible Series NAS Memory
Model nameSynology DDR4 2666 MHz ECC RDIMM Registered Server Memory
Part numberMR21300-614K16
Total capacity256 GB (16 × 16 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 rank1Rx4
Power
Rated voltage1.2 V
Compatibility
Compatible systemsSynology
In the box
Included items256 GB (16 × 16 GB) DDR4 2666 MHz PC4-21300 1Rx4 1.2 V CL19 288-PIN ECC RDIMM Registered Server Memory

Questions about this item

How much power does the 1.20 V DDR4 2666 kit draw when the FS6400 runs continuously?

Each 16 GB module operates at 1.20 V; total draw depends on the FS6400 memory controller and workload, not on the modules alone.

What must the Synology FS6400 already have installed to accept this 16 x 16 GB ECC RDIMM kit?

The FS6400 must support DDR4 2666 registered ECC RDIMMs and provide 16 free 288-pin slots for the 1Rx4 modules.

Can I keep my existing lower-speed DDR4 RDIMMs in the FS6400 while adding this CL19 2666 MHz kit?

Mixing ranks, speeds or latencies is not recommended; the FS6400 will run all channels at the slowest installed module.

More in Model-Specific Memory Upgrades

Similar items