Side-by-side specifications of the Synology DS409slim and DS410, from official datasheets. Differences are highlighted.
| DS409slim | DS410 | |
| CPU | 1.2GHz | 1.06GHz |
| Cores / threads | — | — |
| RAM (base) | 128MB | 512MB |
| RAM (max) | 128MB | 512MB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | — |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 3TB | 12TB |
| Hot-swap | yes | yes |
| Form factor | 2.5" NAS | desktop |
| Released | 2010 | 2010 |
Choose the DS410 if you want a far more capable box: it has a 1.6 GHz CPU and up to 1 GB RAM, versus the DS409slim’s much weaker ARM CPU and 128 MB RAM ceiling. The DS410 also gives you 4 bays with room to grow, while the DS409slim is a 4-bay compact unit with no expansion advantage; neither model has built-in 10GbE or M.2. If you care about speed, multitasking, and longevity, the DS410 is the clear pick.