Side-by-side specifications of the Synology RS3617xs+ and RS3618xs, from official datasheets. Differences are highlighted.
| RS3617xs+ | RS3618xs | |
| CPU | Intel Xeon D-1531 2.2 GHz | Intel Xeon D-1521 |
| Cores / threads | 6 cores / 12 threads | 4 cores / 8 threads |
| RAM (base) | 8 GB DDR4 ECC UDIMM | 8 GB DDR4 ECC UDIMM |
| RAM (max) | 64 GB | 64 GB |
| Drive bays | 12 | 12 |
| Expandable to | 24 (2× RX1217/RX1217RP) | 36 total with 2 expansion units |
| M.2 slots | 0 | 0 |
| Network | 4× 1GbE RJ-45; 2× 10GBase-T RJ-45 | 4 × 1GbE RJ-45 |
| 10GbE | yes | optional |
| Max raw capacity | 360 TB | 216 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2017 | 2018 |
| Power consumption | — | 142.76 W / 55.05 W |
| DSM at launch | — | — |