Side-by-side specifications of the Synology DS115 and DS218j, from official datasheets. Differences are highlighted.
| DS115 | DS218j | |
| CPU | Marvell Armada 375 | Marvell Armada 385 88F6820 |
| Cores / threads | 2 | 2-core |
| RAM (base) | 512MB DDR3 | 512 MB |
| RAM (max) | 512MB | 512 MB |
| Drive bays | 1 | 2 |
| Expandable to | 0 | — |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x 1GbE |
| 10GbE | no | no |
| Max raw capacity | 6TB | 20TB |
| Hot-swap | no | no |
| Form factor | desktop | desktop |
| Released | 2014 | 2018 |