OWC
16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC Unbuffered SODIMM 1.2V 260-pin Memory RAM Compatible with Synology D4ECSO-2666-16G, D4ES01-16G
*Price sourced from Amazon.com. Last updated 2026-05-26. Price and availability subject to change.
Bottom line: The 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC Unbuffered SODIMM 1.2V 260-pin Memory RAM Compatible with Synology D4ECSO-2666-16G, D4ES01-16G is a category leader on buyer feedback in the memory & ram category, priced around $157.86, rated 4.6★ across 50 verified Amazon reviews. A confident buy for most shoppers in this category.
SpecPicks Verdict
SpecPicks classifies OWC 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC Unbuffered SODIMM 1.2V… as a category leader on buyer feedback in the memory & ram category, based on 50 verified Amazon reviews and our ranking model that weights rating × review-volume × price-fit. OWC's positioning sits comfortably above the category median. Use the Compare tool to put it side-by-side with two or three close alternatives before clicking through to Amazon.
Common buyer scenarios for memory & ram of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the Amazon listing before purchase. Prices, stock, and Prime eligibility update directly from Amazon's catalog and may have moved since this page was last verified.
Pros & Cons
Pros
- ✓ Highly rated — 4.6★ average across customer reviews
- ✓ Backed by OWC's warranty and support channels
- ✓ Ships via Amazon with Prime eligibility and the standard returns policy
Cons
- ✗ Confirm socket / form-factor / power-rating compatibility against your build before ordering
- ✗ Price, stock, and Prime eligibility update from Amazon and may have changed since this page was last verified
Key Features
- OWC 16GB UPGRADE: Consists of a single 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC SO-DIMM 1.2V 260-pin Memory Module
- Compatible with Synology Part D4ECSO-2666-16G, Compatible with the following Synology machines: DS3617xsII; DS1621+; DS1821+; DS2419+II
- INCREASED PERFORMANCE: Memory Upgrades are the Most Effective and Easy Way to Boost the Performance of Your Server, Micro Server or NAS System
- INDUSTRY LEADING: Consumer Friendly Advanced Replacement Program and Limited Lifetime Warranty, which Includes Free Tech Support by Other World Computing
- EASY INSTALLATION: In Most Cases Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for help.
Full Specifications
| Brand | OWC |
|---|---|
| Weight | 16g |
| Voltage | 1.2 Volts |
| RAM Size | 16 GB |
| Model Name | OWC Memory |
| Form Factor | SO-DIMM |
| Memory Speed | 2666 MHz |
| Model Number | OWC2C6D42R816GB |
| Number of Pins | 260 |
| Mfr Part Number | OWC2C6D42R816GB |
| INDUSTRY LEADING | Consumer Friendly Advanced Replacement Program and Limited Lifetime Warranty, which Includes Free Tech Support by Other World Computing |
| OWC 16GB UPGRADE | Consists of a single 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC SO-DIMM 1.2V 260-pin Memory Module |
| EASY INSTALLATION | In Most Cases Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for help. |
| Memory Generation | DDR4 |
Ready to buy?
OWC 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC Unbuffered SODIMM 1.2V 260-pin Memory RAM Compatible with Synology D4ECSO-2666-16G, D4ES01-16G is available on Amazon with Prime shipping and the full Amazon returns policy. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-05-26. Price and availability subject to change.
Related Memory & RAM
