Side-by-side specifications of the Synology RS2211+ and RS2211RP+, from official datasheets. Differences are highlighted.
| RS2211+ | RS2211RP+ | |
| CPU | Dual Core 1.8 GHz with floating point | Dual Core 1.8 GHz |
| Cores / threads | 2 cores / unknown threads | 2 cores / 2 threads |
| RAM (base) | 1 GB DDR2 | 1 GB DDR2 |
| RAM (max) | 3 GB | 3 GB |
| Drive bays | 10 | 10 |
| Expandable to | 12 | 12 |
| M.2 slots | 0 | 0 |
| Network | 2x Gigabit Ethernet | 2x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 30 TB internal; 66 TB with RX1211 expansion | 30 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2011 | 2011 |
| Power consumption | — | — |
| DSM at launch | — | — |
The RS2211RP+ is the safer choice if you want redundant power; otherwise, the RS2211+ is the same core unit with no dual-PSU failover. For these models, the deciding specs are essentially the same: Intel Atom CPU, 3 GB RAM ceiling, 8 bays with expansion support, and no built-in 10GbE or M.2 slots. Choose only based on power redundancy, since performance and expansion are otherwise effectively identical.