Side-by-side specifications of the Synology DS423+ and DS509+, from official datasheets. Differences are highlighted.
| DS423+ | DS509+ | |
| CPU | Intel Celeron J4125 | Intel Celeron |
| Cores / threads | 4 | — |
| RAM (base) | 2 GB | 512 MB |
| RAM (max) | 6 GB | 512 MB |
| Drive bays | 4 | 5 |
| Expandable to | 0 | 10 |
| M.2 slots | 2 | 0 |
| Network | 2 x 1GbE RJ-45 | 2x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 108 TB | 30 TB |
| Hot-swap | yes | yes |
| Form factor | Desktop | desktop |
| Released | 2023 | 2009 |