Side-by-side specifications of the Synology DS413 and DS413j, from official datasheets. Differences are highlighted.
| DS413 | DS413j | |
| CPU | Dual-core | Marvell Armada 370 |
| Cores / threads | 2 | 1/1 |
| RAM (base) | 512MB | 512 MB |
| RAM (max) | 512MB | 512 MB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 16TB | 16 TB |
| Hot-swap | yes | yes |
| Form factor | Desktop | Desktop |
| Released | 2012 | 2013 |
Pick the DS413 if you want the clearly stronger box: it has the faster CPU, more RAM headroom, and supports 10GbE, while still being a 4-bay unit with no M.2 slots or expansion. The DS413j is the budget choice with a weaker CPU and lower RAM ceiling; it is also 4-bay and has no 10GbE, M.2, or expansion, so it’s fine for light file backup/media use but not much else.