Side-by-side specifications of the Synology DS216se and DS218, from official datasheets. Differences are highlighted.
| DS216se | DS218 | |
| CPU | Marvell Armada 370 800MHz | Realtek RTD1296 |
| Cores / threads | — | 4-core |
| RAM (base) | 256MB DDR3 | 2 GB |
| RAM (max) | 256MB | 2 GB |
| Drive bays | 2 | 2 |
| Expandable to | 0 | — |
| M.2 slots | 0 | — |
| Network | 1x Gigabit RJ-45 | 1x 1GbE |
| 10GbE | no | no |
| Max raw capacity | 16TB | 20TB |
| Hot-swap | yes | yes |
| Form factor | desktop | desktop |
| Released | 2016 | 2018 |
Choose the DS218: it has a much faster Realtek RTD1296 quad-core CPU and 2 GB RAM vs the DS216se’s much weaker single-core Marvell chip and 256 MB RAM, so it will handle file services and apps far better. Both are 2-bay NAS units and neither has expansion bays, 10GbE, or M.2 slots; the DS218 only adds practical headroom, not extra hardware expansion.