Side-by-side specifications of the Synology RS3617xs and RS4017xs+, from official datasheets. Differences are highlighted.
| RS3617xs | RS4017xs+ | |
| CPU | Intel Xeon E3-1230v2 3.3GHz | Intel Xeon D-1541 |
| Cores / threads | 4/8 | 8c/16t |
| RAM (base) | 4GB | 8GB |
| RAM (max) | 32GB | 64GB |
| Drive bays | 12 | 16 |
| Expandable to | 36 | 40 |
| M.2 slots | 0 | 0 |
| Network | 4x1GbE | 2x 10GbE RJ-45 + 4x 1GbE RJ-45 |
| 10GbE | optional | yes |
| Max raw capacity | 96TB | 400 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 3U |
| Released | 2015 | 2017 |