Side-by-side specifications of the Synology RS3614xs and RS3617xs+, from official datasheets. Differences are highlighted.
| RS3614xs | RS3617xs+ | |
| CPU | Intel Core i3 Dual Core 3.4GHz | Intel Xeon D-1531 2.2 GHz |
| Cores / threads | 2 cores / 4 threads | 6 cores / 12 threads |
| RAM (base) | 4GB DDR3 ECC | 8 GB DDR4 ECC UDIMM |
| RAM (max) | 32GB | 64 GB |
| Drive bays | 12 | 12 |
| Expandable to | 24 | 24 (2× RX1217/RX1217RP) |
| M.2 slots | 0 | 0 |
| Network | 4x Gigabit | 4× 1GbE RJ-45; 2× 10GBase-T RJ-45 |
| 10GbE | optional | yes |
| Max raw capacity | 216TB | 360 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2014 | 2017 |
| Power consumption | — | — |
| DSM at launch | — | — |
Choose the RS3617xs+ if you want the newer/faster platform: it has a newer Intel Xeon CPU, higher RAM ceiling, and better expansion support than the RS3614XS. It also adds native 10GbE and M.2/NVMe cache support, while the RS3614XS is older, tops out lower on memory, and lacks those features. If you need more future-proofing and performance for a home/SMB NAS, the RS3617xs+ is the clear pick.