Side-by-side specifications of the Synology DS213j and DS213+, from official datasheets. Differences are highlighted.
| DS213j | DS213+ | |
| CPU | Marvell Kirkwood 1.2GHz | Marvell Armada XP MV78230 dual-core 1.0 GHz |
| Cores / threads | 1 core / 1 thread | 2 cores / 2 threads |
| RAM (base) | 512MB DDR3 | 512 MB DDR3 |
| RAM (max) | 512MB | 512 MB |
| Drive bays | 2 | 2 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 0 |
| Network | 1× Gigabit | 1× Gigabit Ethernet |
| 10GbE | no | no |
| Max raw capacity | 8TB (2×4TB) | 8 TB (2×4 TB) |
| Hot-swap | no | yes |
| Form factor | Desktop | tower |
| Released | 2013 | 2013 |
| Power consumption | 19.82 W / 3.65 W | 18.4 W / 2.6 W |
| DSM at launch | — | 4.2 |
Choose the DS213+ if you want the faster CPU and the higher RAM ceiling; it’s the better pick for heavier multitasking, but both units still have the same 2 bays and no expansion. Neither the DS213+ nor DS213j has 10GbE or M.2, so those features don’t help decide between them.