Side-by-side specifications of the Synology DS210J and DS211, from official datasheets. Differences are highlighted.
| DS210J | DS211 | |
| CPU | 800MHz | 1.6GHz |
| Cores / threads | — | — |
| RAM (base) | 128 MB | 256MB |
| RAM (max) | 128 MB | 256MB |
| Drive bays | 2 | 2 |
| Expandable to | no | — |
| M.2 slots | 0 | 0 |
| Network | 1x Gigabit | 1x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 4 TB | 6TB |
| Hot-swap | yes | no |
| Form factor | desktop | desktop |
| Released | 2009 | 2010 |
Choose the DS211: it has a much faster 1.6 GHz Marvell Kirkwood CPU and 256 MB RAM versus the DS210j’s 1.2 GHz CPU and 128 MB RAM, so it’s noticeably better for multi-user use and heavier tasks. Both are 2-bay units with no expansion, and neither supports 10GbE or M.2.