Side-by-side specifications of the Synology DS420j and DS509+, from official datasheets. Differences are highlighted.
| DS420j | DS509+ | |
| CPU | Realtek RTD1296 | Intel Celeron |
| Cores / threads | 4-core | — |
| RAM (base) | 1 GB DDR4 | 512 MB |
| RAM (max) | 1 GB | 512 MB |
| Drive bays | 4 | 5 |
| Expandable to | 0 | 10 |
| M.2 slots | 0 | 0 |
| Network | 1 x 1GbE RJ-45 | 2x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 64 TB | 30 TB |
| Hot-swap | no | yes |
| Form factor | desktop | desktop |
| Released | 2023 | 2009 |