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
Eight green circuit boards with gold contacts and black chips in a clear tray

OWC

OWC 256GB (8x32GB) DDR4 2666 ECC Registered RDIMM NAS SA6400 Server RAM

SKU CH-4EAJ-ZC87J

Eight 32 GB DDR4 2666 ECC registered RDIMMs totalling 256 GB for Synology SA6400 NAS and compatible servers

  • Capacity256GB (8 x 32GB)
  • Type288-Pin DDR4 SDRAM
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.2V
  • ECCYes

Capacity 256GB (8 x 32GB)

  • ECC registered design protects data integrity in servers
  • 256GB total capacity across eight 32GB modules for heavy workloads
  • DDR4 2666 CL19 at 1.2V delivers efficient performance
  • JEDEC and RoHS compliant for warranty-safe upgrades
  • Backward compatible with 2133MHz and 2400MHz systems

OWC 256GB DDR4 2666 ECC Registered Kit

This 256GB kit contains eight 32GB DDR4 2666 registered DIMMs built for Synology SA6400 NAS units and compatible servers. ECC registered memory detects and corrects single-bit errors to protect data integrity in always-on workloads. It will not work in standard desktop computers or alongside unbuffered or load-reduced modules. Buyers needing non-ECC or consumer DIMMs should look elsewhere.

Capacity and headroom for NAS workloads

Eight modules populate eight slots to deliver 256GB total capacity at 2666MHz CL19. The kit runs at 1.2V and is backward compatible with 2133MHz and 2400MHz bus speeds. Headroom is defined by the 288-pin registered form factor and the SA6400 memory controller; larger configurations or faster speeds are not supported by this platform. Systems requiring more than 256GB or higher-frequency modules cannot use this kit.

JEDEC compliance and lifetime support

Modules meet JEDEC and RoHS standards for a warranty-safe upgrade without voiding the original system warranty. OWC provides a limited lifetime warranty with free technical support and an advanced replacement programme. No heat spreaders are included; cooling relies on chassis airflow. The bundle contains only the eight memory modules — no software, cables or additional accessories are supplied.

Highlights

  • ECC registered design protects data integrity in servers
  • 256GB total capacity across eight 32GB modules for heavy workloads
  • DDR4 2666 CL19 at 1.2V delivers efficient performance
  • JEDEC and RoHS compliant for warranty-safe upgrades
  • Backward compatible with 2133MHz and 2400MHz systems

Specifications

BrandOWC
Part Number2R6D42R4256K
Capacity256GB (8 x 32GB)
Type288-Pin DDR4 SDRAM
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.2V
ECCYes
Buffered/RegisteredRegistered
Rank2Rx4
Multi-channel KitDual Channel Kit
Heat SpreaderNo

Other versions of this model

5 more in the same range

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

Questions about this item

Will the 2666 MHz RDIMMs run reliably alongside my existing 2133 MHz or 2400 MHz ECC registered modules?

Yes — the kit is backward compatible with 2133 MHz and 2400 MHz DDR4 ECC registered DIMMs; all modules will operate at the speed of the slowest installed kit.

How can I verify the 256 GB kit is detected and ECC is active after installation in my SA6400?

Check the DSM Resource Monitor or BIOS POST screen — it should show 256 GB total at 2666 MHz with ECC status reported as enabled or corrected errors counting.

Does the 8-module box include any heat spreaders, cables or tools, or must I buy them separately?

The package contains only the eight 32 GB 288-pin DDR4 RDIMMs (CL19, 1.2 V, 2Rx4); no heat spreaders, cables or installation tools are included.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.