Side-by-side specifications of the Synology DS212J and DS213, from official datasheets. Differences are highlighted.
| DS212J | DS213 | |
| CPU | Marvell 6281 | Marvell Armada 370 |
| Cores / threads | 1/1 | 1/1 |
| RAM (base) | 256MB | 512 MB |
| RAM (max) | 256MB | 512 MB |
| Drive bays | 2 | 2 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 6TB | 8 TB |
| Hot-swap | no | yes |
| Form factor | desktop | desktop |
| Released | 2011 | 2013 |
Choose the DS213 if you want the better long-term box: it has a faster CPU and higher RAM ceiling than the DS212J, while both are still 2-bay units with no expansion path. Neither model has 10GbE or M.2, so those aren’t deciding factors here.