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Two green DDR4 ECC UDIMM sticks, 288-pin, no heat spreader

OWC

OWC 16GB (2x8GB) DDR4 2666 ECC UDIMM Kit memory upgrade

SKU CH-G484-HZ78H

A 16GB DDR4 ECC UDIMM kit with two 8GB modules at 2666MHz CL19 for Synology RackStation RS3621RPxs and RS3621xs+

  • Capacity16GB (2 x 8GB)
  • Type288-Pin DDR4 ECC UDIMM
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.2V
  • ECCYes

Capacity 16GB (2 x 8GB)

  • 8GB
  • 16GB (2 x 8GB)
  • 32GB (2 x 16GB)
  • 64GB (4 x 16GB)

Struck-through versions exist but are not stocked here.

  • 16 GB dual-channel kit for Synology RS3621RPxs and RS3621xs+
  • DDR4 2666 MHz CL19 ECC unbuffered for data integrity
  • JEDEC and RoHS compliant warranty-safe upgrade
  • Low 1.2 V operation reduces power draw
  • Backward compatible with 2133 MHz and 2400 MHz systems

Compatible Synology RackStation upgrade

This 16 GB kit contains two 8 GB DDR4 2666 ECC UDIMM modules built for Synology RackStation RS3621RPxs and RS3621xs+ systems. It targets administrators who need to expand memory capacity on these specific NAS platforms without changing voltage or form factor. The 288-pin unbuffered design matches the factory slot layout exactly.

Thermals noise and power profile

Modules run at the standard 1.2 V DDR4 voltage and carry no heat spreader, so they rely on the chassis airflow already present in the RackStation. JEDEC-compliant CL19 timing keeps power draw predictable during sustained file-service workloads. The unbuffered ECC design adds error correction without the extra register latency of registered DIMMs.

When the upgrade makes sense

The kit replaces or supplements the original memory when workloads such as virtual machines, Docker containers or large-volume file indexing exceed the stock capacity. Backward compatibility with 2133 MHz and 2400 MHz systems means the same modules work if the platform is later repurposed. Buyers who need registered DIMMs or capacities beyond 16 GB per kit must look elsewhere.

Highlights

  • 16 GB dual-channel kit for Synology RS3621RPxs and RS3621xs+
  • DDR4 2666 MHz CL19 ECC unbuffered for data integrity
  • JEDEC and RoHS compliant warranty-safe upgrade
  • Low 1.2 V operation reduces power draw
  • Backward compatible with 2133 MHz and 2400 MHz systems

Specifications

BrandOWC
Part Number2E6D41R8016P
Capacity16GB (2 x 8GB)
Type288-Pin DDR4 ECC UDIMM
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.2V
ECCYes
Buffered/RegisteredUnbuffered
Rank1Rx8
Heat SpreaderNo
Compatible SystemSynology RackstationRS3621RPxs
Synology RackstationRS3621xs+

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

How do I install the 288-pin DDR4 ECC UDIMM modules in my Synology RS3621RPxs, and what step is often missed?

Power off the NAS, open the chassis, align each module's notch with the slot key, press firmly until both side clips click, then verify in DSM that 16 GB is recognised at 2666 MHz.

What maintenance or replacement will this ECC UDIMM kit need over time?

No scheduled maintenance is required; the modules run at 1.2 V without heat spreaders, so keep the NAS vents clean and replace only if a memory error appears in system logs.

What limit appears first when the RS3621xs+ runs sustained workloads with this CL19 memory?

The CAS latency of 19 cycles at 2666 MHz sets the baseline response time; under heavy multi-threaded loads the memory controller bandwidth ceiling is reached before thermal throttling occurs.

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