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Green circuit board with gold contacts and black memory chips, no heat spreader

OWC

OWC 16GB DDR4 2666 ECC UDIMM CL19 1.2V 2Rx8 Synology RS4017xs+ RS4021xs+

SKU CH-YRGQ-YHPQR

16 GB DDR4 2666 ECC UDIMM module for Synology RS4017xs+ and RS4021xs+ NAS

  • Total capacity16 GB (1 × 16 GB)
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latencyCL19
  • Rated voltage1.2 V
  • Buffer typeUnbuffered
  • Memory rank2Rx8
  • 16 GB capacity expands NAS memory for heavier workloads
  • DDR4 2666 MHz CL19 timing keeps data flowing at rated speed
  • ECC unbuffered design detects and corrects single-bit errors automatically
  • 2 V operation lowers power draw and heat output
  • Validated for Synology RS4017xs+ and RS4021xs+ systems

Compatible Synology RackStation upgrade

This 16GB DDR4 ECC UDIMM is validated for the Synology RS4017xs+ and RS4021xs+ platforms. It provides a single-module capacity increase for NAS, rackmount and NVR workloads that require error-correcting memory. The module follows the standard 288-pin unbuffered form factor. Builders needing non-ECC memory or a different pin count cannot use this part.

Thermals and power in normal operation

Operating at 1.2V, the module runs at the standard DDR4 voltage without a heat spreader. Passive cooling inside the chassis is sufficient for typical 2666MHz operation. Power draw scales with the 2Rx8 organisation and CL19 timing during sustained file-serving tasks. No active cooling or extra airflow is specified by the manufacturer.

What the compliance and support change

JEDEC and RoHS compliance make the upgrade warranty-safe for the target RackStation models. Backward compatibility with 2133MHz and 2400MHz systems allows the same module to work in slower slots. The supplier’s advanced replacement programme and limited lifetime warranty include free technical support for installation questions. No software utilities or additional accessories are bundled.

How it compares

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

Price $121.99
Cheaper than about 65% of the 21,161 comparable items (median $397.99).
Total capacity 16 GB (1 × 16 GB)
Lower than about 70% of the 20,941 comparable items (median 32 GB).
Price per GB $7.62 per GB
Typical for this category: the median of 20,941 items is $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 nameOWC
Part number2E6D42R816 GB
Total capacity16 GB (1 × 16 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 RackstationRS4017xs+
Synology RackstationRS4021xs+

Questions about this item

How do I install the 288-pin DDR4 2666 ECC UDIMM in my Synology RS4017xs+ and what step is often missed?

Power down the NAS, open the chassis, align the notch on the 288-pin module with the slot key, press firmly until the retention clips click, then power on and verify the new 16GB appears in DSM — the step often missed is fully seating both clips so ECC initialisation succeeds.

What maintenance or replacement will this 16GB DDR4 2666 CL19 1.2V 2Rx8 module need later?

No scheduled maintenance is required; the module has no heat spreader and runs at 1.2V, so only replace it if a memory test reports correctable ECC errors rising above threshold or if you need more than 16GB per slot.

What limit appears first when the RS4021xs+ runs sustained workloads with this PC4-21300 CL19 ECC UDIMM?

The memory controller caps operation at 2666 MT/s CL19; sustained heavy use will hit bandwidth and latency limits of the DDR4 2666 specification before thermal throttling occurs on the unbuffered 2Rx8 module.

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