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Green rectangular circuit board with gold edge contacts and black memory chips

OWC

OWC 8GB DDR4 2666 CL19 1Rx8 ECC UDIMM memory upgrade

SKU CH-CSCC-T2XGG

Adds 8 GB of DDR4 ECC UDIMM memory at 2666 MHz CL19 for Synology NAS and Unified Controller systems

  • Capacity8GB
  • Type288-Pin DDR4 ECC UDIMM
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.2V
  • ECCYes

Capacity 8GB

  • 8GB
  • 16GB

Struck-through versions exist but are not stocked here.

  • ECC protection guards data integrity on Synology NAS
  • 8 GB single module expands memory capacity simply
  • 2666 MHz DDR4 speed matches system specifications
  • 2 V low voltage reduces power draw
  • 288-pin UDIMM form factor fits UC3400 and DS series

Synology UC3400 memory upgrade

This 8 GB DDR4 2666 ECC UDIMM is built for the Synology Unified Controller UC3400 and compatible DiskStation models including the DS1825+, DS1825xs+, DS725+ and DS925+. It replaces Synology part numbers D4EC-2666-8G and D4EU01-8G for a direct, warranty-safe capacity increase.

JEDEC and RoHS compliance

The module meets JEDEC-standard PC4-21300 timing at CL19 and runs at the standard 1.2 V. RoHS compliance and OWC in-house validation mean the upgrade keeps the original system warranty intact while adding error-correcting protection for stored data.

8 GB single-rank headroom

A single 1Rx8 rank adds 8 GB of ECC-protected memory to the controller or NAS, improving multi-tasking and large-file handling. The module also runs at 2133 MHz or 2400 MHz when the platform requires a lower speed, but capacity stops at this 8 GB stick.

Highlights

  • ECC protection guards data integrity on Synology NAS
  • 8 GB single module expands memory capacity simply
  • 2666 MHz DDR4 speed matches system specifications
  • 2 V low voltage reduces power draw
  • 288-pin UDIMM form factor fits UC3400 and DS series

Specifications

BrandOWC
Part Number2E6D41R808GB
Capacity8GB
Type288-Pin DDR4 ECC UDIMM
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.2V
ECCYes
Buffered/RegisteredUnbuffered
Rank1Rx8
Heat SpreaderNo
Compatible SystemSynology Unified Controller UC3400
Synology DiskStation DS1825+
Synology DiskStation DS1825xs+
Synology DiskStation DS725+
Synology DiskStation DS925+

Other versions of this model

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Same family, different memory, cooler or clock — compare before you commit.

Questions about this item

Will the 8GB DDR4 2666 ECC UDIMM need any firmware updates or module replacement after installation?

The module is JEDEC-standard and requires no firmware updates. As a non-volatile memory component, it has no moving parts or wear items that need scheduled replacement under normal operation.

What limit appears first when the Synology UC3400 runs sustained workloads with this 1Rx8 CL19 module?

The CAS latency of CL19 at 2666 MHz sets the timing ceiling. Under continuous load, the memory controller will hit this latency boundary before bandwidth saturation occurs on the PC4-21300 interface.

How much heat and power does the 1.2V unbuffered DIMM produce during all-day operation in a DS925+?

At 1.2 V the module draws minimal power and runs without a heat spreader. Typical DDR4 ECC UDIMMs at this voltage stay cool enough for passive airflow in NAS chassis during 24/7 use.

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