Side-by-side specifications of the Synology DS109 and DS109J, from official datasheets. Differences are highlighted.
| DS109 | DS109J | |
| CPU | 1.2GHz | Marvell 88F6281 |
| Cores / threads | — | 1/1 |
| RAM (base) | 128 MB | 128MB |
| RAM (max) | 128 MB | 128MB |
| Drive bays | 1 | 1 |
| Expandable to | no | 0 |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 2 TB | 2TB |
| Hot-swap | no | no |
| Form factor | desktop | desktop |
| Released | 2008 | 2009 |