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Green circuit board with gold edge connectors and black memory chips

OWC

OWC 16GB DDR4 2666 ECC UDIMM memory upgrade

SKU CH-36FT-1G4H8

A 16 GB DDR4 2666 ECC UDIMM module for Synology UC3400, DS1825+, DS1825xs+, DS725+ and DS925+ systems

  • Total capacity16 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latencyCL19
  • Rated voltage1.2 V
  • Buffer typeUnbuffered
  • Memory rank2Rx8
  • ECC protection prevents data errors in critical NAS workloads
  • 16 GB capacity expands memory for heavier multitasking
  • 2666 MHz DDR4 speed matches Synology UC3400 and DS series specs
  • 2 V low voltage reduces power draw and heat
  • 288-pin UDIMM form factor fits compatible Synology systems directly

Synology NAS ECC memory upgrade

This 16GB DDR4 module is built for Synology Unified Controller UC3400 and DiskStation DS725+, DS925+, DS1825+ and DS1825xs+ systems. It delivers error-correcting code protection for data integrity in always-on storage appliances. The unbuffered design fits standard 288-pin DDR4 slots without requiring registered memory support. It suits administrators who need reliable capacity expansion for virtualisation or heavy file workloads.

Single DIMM slot population

The module occupies one 288-pin UDIMM slot and runs at 1.2V, matching the platform's standard voltage. No heat spreader is fitted, so clearance inside compact NAS chassis remains uncomplicated. Backward compatibility with 2133MHz and 2400MHz buses lets it deploy in mixed-speed configurations without manual down-clocking. Installers simply seat the DIMM and the system applies JEDEC timings automatically.

16GB capacity with CL19 latency

At 2666MHz PC4-21300 CL19 the stick adds 16GB of ECC-protected address space for caching, container hosts or large volume metadata. The dual-rank 2Rx8 organisation maximises density per slot, leaving additional slots free for further expansion. Systems already at the platform's maximum supported memory will not benefit from this module. Buyers needing more than one DIMM per channel should verify slot count before ordering.

How it compares

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

Price $117.99
Cheaper than about 65% of the 21,161 comparable items (median $397.99).
Total capacity 16 GB
Lower than about 70% of the 20,941 comparable items (median 32 GB).
Price per GB $7.37 per GB
Cheaper than about 55% of the 20,941 comparable items (median $8.19 per GB).

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Specifications

Product
Brand nameOWC
Part number2E6D42R816 GB
Total capacity16 GB
Product type288-Pin DDR4 ECC UDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Memory
CAS latencyCL19
ECC supportYes
Buffer typeUnbuffered
Memory rank2Rx8
Heat spreaderNo
Power
Rated voltage1.2 V
Compatibility
Compatible systemsSynology Unified Controller UC3400
Synology DiskStation DS1825+
Synology DiskStation DS1825xs+
Synology DiskStation DS725+
Synology DiskStation DS925+

Other versions of this model

5 more in the same range

Questions about this item

How much capacity does the single 2Rx8 DDR4 2666 module add?

The module adds 16GB of ECC unbuffered memory running at 1.2V with CL19 latency.

Does the module include a heat spreader for all-day operation in a NAS?

No heat spreader is fitted; the JEDEC-standard 1.2V DDR4 design runs within spec without one.

Which Synology systems must the buyer already own for this upgrade to work?

Compatible systems are Synology Unified Controller UC3400, DS1825+, DS1825xs+, DS725+ and DS925+.

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