Synology 16GB DDR4 2666 MHz ECC SO-DIMM Memory Module

The Synology D4ECSO-2666-16G is a 16 GB memory module that installs in the SO-DIMM slot of many Synology NAS models to give them extra headroom for demanding workloads. It runs at 2666 MHz, so tasks like file indexing, photo management, or running multiple Docker containers feel more responsive. Because the module uses Error-Correcting Code (ECC) technology, it can detect and correct common memory errors on the fly, helping protect long backups, large databases, and virtual machines from silent data corruption.

This module is engineered by Synology for Synology, which removes the guesswork that often comes with third-party RAM. Systems such as the DS1621+, DS1819+, DS3018xs, and FS1018 recognize the module automatically, so installation is as simple as shutting down the NAS, seating the SO-DIMM, and powering back on. If you run Plex, host virtual environments, or manage surveillance footage, the added capacity lets you keep more services running at once without the slowdowns that come from memory paging.

Small businesses that rely on shared folders and real-time collaboration will notice quicker opening of large documents and reduced lag during peak use. Home power users can stream 4K media, back up family devices, and manage smart-home logs all at the same time. Whether your NAS has a single slot that needs a direct upgrade or several slots ready for expansion, this module offers a straightforward path to better performance and improved stability, though some models may operate the module in non-ECC mode if ECC support is not available.

• 16 GB module that uses DDR4 technology with a 2666 MHz clock speed
• ECC support helps detect and correct memory errors for greater data integrity
• SO-DIMM form factor that fits designated Synology NAS slots with no modification
• Officially qualified for models such as DS1621+, DS1819+, DS3018xs, FS1018, and others
• Dual-rank layout with a very low profile that clears internal NAS components
• Unbuffered and non-registered design for straightforward installation
• Ideal for multitasking environments that run virtual machines, media servers, or heavy backup jobs
• Operates in non-ECC mode on NAS models that do not support ECC even when the module is installed