Side-by-side specifications of the Synology RS815 and RS815RP+, from official datasheets. Differences are highlighted.
| RS815 | RS815RP+ | |
| CPU | Intel Atom C2538 | Intel Atom C2538 |
| Cores / threads | 4 | 4c/4t |
| RAM (base) | 1 GB | 2 GB |
| RAM (max) | 1 GB | 6 GB |
| Drive bays | 4 | 4 |
| Expandable to | 8 | 8 |
| M.2 slots | 0 | 0 |
| Network | 2x Gigabit | 4x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 32 TB | 24 TB |
| Hot-swap | yes | yes |
| Form factor | 1U rackmount | 1U rackmount |
| Released | 2014 | 2015 |