SO-DIMM 4 GB DDR4-2666, per Serie 21:RS1221RP+, RS1221+, DS1821+, DS1621+ (D4ES01-4G)

The Synology DDR4 4 GB 1 x 4 GB ECC memory module (D4ES01-4G) is a single-module solution intended to increase system stability and support data integrity in compatible Synology systems and other ECC-capable servers or workstations. This 4 GB DDR4 module uses error-correcting code (ECC) to detect and correct common types of internal data corruption, and its DDR4 architecture provides improved data transfer efficiency and lower power consumption compared with older memory generations.

Advantages

The module offers error-correcting capabilities to reduce the risk of data corruption and unexpected crashes, contributing to higher uptime for storage systems and servers. As a DDR4 unit, it supports faster memory clocks and improved throughput while operating at reduced voltage, which can lead to better energy efficiency. The single 4 GB configuration makes it straightforward to add or replace memory in systems that accept ECC DDR4 DIMMs.

Suitable for

• Small to medium Synology NAS systems that specify compatible ECC DDR4 memory
• Entry-level servers and workstations requiring ECC support
• Environments where data integrity and system stability are priorities

Key specifications

• Memory capacity: 4 GB
• Memory type: DDR4
• Form factor: single module (1 x 4 GB)
• ECC: error-correcting code support for detection and correction of memory errors

How to use

Before installation, power down the host system and disconnect all power sources. Open the system chassis according to the manufacturer’s instructions and locate the compatible DDR4 ECC memory slot. Align the module with the slot keyed edge and press firmly until the module latches into place. Reassemble the chassis, reconnect power, and boot the system. Confirm the new memory is recognised in the system firmware or operating system memory information screens.

Recommendations

Install this Synology 4 GB DDR4 ECC module only in systems that explicitly support ECC DDR4 memory and the specific module form factor. For optimal performance and stability, install memory in matched pairs or follow the system vendor’s guidelines for memory population; consult Synology or your system documentation for compatibility lists before purchase.