Side-by-side specifications of the Synology RS409 and RS409RP+, from official datasheets. Differences are highlighted.
| RS409 | RS409RP+ | |
| CPU | 1.2GHz | Intel x86 |
| Cores / threads | — | — |
| RAM (base) | 256MB | 512 MB |
| RAM (max) | — | 1 GB |
| Drive bays | 4 | 4 |
| Expandable to | 8 | 8 |
| M.2 slots | 0 | 0 |
| Network | 2x Gigabit | 2x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 3TB internal; 8 bays w/ RX4 | 8 TB |
| Hot-swap | yes | yes |
| Form factor | 1U rackmount | 1U |
| Released | 2009 | 2009 |