SK hynix 16GB DDR4-2666 ECC SO-DIMM 2Rx8 CL19 1.2V

Synology-Certified 16 GB DDR4-2666 ECC SO-DIMM

This 16 GB DDR4-2666 ECC SO-DIMM carries Synology certification for the DS1621+ and similar micro-servers. It targets administrators who need validated error-correcting memory for ZFS or Btrfs volumes. The single 260-pin module delivers 16 GB at PC4-21300 speed with CL19 latency. Buyers who need non-ECC laptop SODIMMs or higher-frequency kits should look elsewhere.

Sustained-load behaviour with 2Rx8 organisation

The dual-rank 2Rx8 layout spreads accesses across sixteen DRAM chips, keeping per-chip current lower during long compile jobs or overnight backup windows. ECC single-bit correction and multi-bit detection run on every transaction, so silent data corruption is caught without software overhead. JEDEC-standard 1.2 V operation limits thermal rise in fanless chassis. Workloads that exceed 16 GB capacity will still swap regardless of rank count.

Straightforward 260-pin installation

The module inserts like any 260-pin SO-DIMM: align the key notch, press until the side clips latch. No BIOS tuning is required; the SPD programs 2666 MT/s at CL19 automatically. The most frequent issue is mixing this ECC stick with non-ECC modules, which disables error correction on many platforms. Another is populating a single slot in a dual-channel board, halving peak bandwidth.