NEMIX RAM 64GB (4×16GB) DDR4 2666 ECC SODIMM Synology DS3617xsII memory upgrade

Synology DS3617xsII 64GB ECC kit

This 64GB kit contains four 16GB DDR4 2666 ECC unbuffered SODIMM modules built for the Synology DiskStation DS3617xsII. Each stick runs at 1.2V with CL19 timing and a 2Rx8 organisation. The ECC design helps protect data integrity in a NAS that runs continuous workloads.

Verify four free SODIMM slots

Before ordering confirm that your DS3617xsII has four available 260-pin SODIMM slots and that the system BIOS accepts DDR4 2666 ECC unbuffered memory at 1.2V. The modules are sold as a matched 4×16GB kit so installing them together avoids mixed-rank or mixed-speed issues. Check the Synology hardware guide for the exact slot population order.

Adds 64GB to a NAS without extra power or cooling

The kit plugs directly into the existing SODIMM sockets and draws standard 1.2V DDR4 power so no additional power connectors or cooling changes are required. Adding 64GB frees the system from memory pressure during heavy file serving virtualization or container tasks. The unbuffered ECC design keeps the signal path simple while still providing error correction for critical data.