OWC 16GB DDR4 2666 ECC UDIMM memory upgrade

Synology NAS ECC memory upgrade

This 16GB DDR4 module is built for Synology Unified Controller UC3400 and DiskStation DS725+, DS925+, DS1825+ and DS1825xs+ systems. It delivers error-correcting code protection for data integrity in always-on storage appliances. The unbuffered design fits standard 288-pin DDR4 slots without requiring registered memory support. It suits administrators who need reliable capacity expansion for virtualisation or heavy file workloads.

Single DIMM slot population

The module occupies one 288-pin UDIMM slot and runs at 1.2V, matching the platform's standard voltage. No heat spreader is fitted, so clearance inside compact NAS chassis remains uncomplicated. Backward compatibility with 2133MHz and 2400MHz buses lets it deploy in mixed-speed configurations without manual down-clocking. Installers simply seat the DIMM and the system applies JEDEC timings automatically.

16GB capacity with CL19 latency

At 2666MHz PC4-21300 CL19 the stick adds 16GB of ECC-protected address space for caching, container hosts or large volume metadata. The dual-rank 2Rx8 organisation maximises density per slot, leaving additional slots free for further expansion. Systems already at the platform's maximum supported memory will not benefit from this module. Buyers needing more than one DIMM per channel should verify slot count before ordering.