Side-by-side specifications of the Synology RS2416RP+ and RS2421+, from official datasheets. Differences are highlighted.
| RS2416RP+ | RS2421+ | |
| CPU | Intel Atom C2538 | AMD Ryzen V1500B |
| Cores / threads | 4 | 4 cores |
| RAM (base) | 2GB | 4 GB |
| RAM (max) | 6GB | 32 GB |
| Drive bays | 12 | 12 |
| Expandable to | 24 | 24 |
| M.2 slots | 0 | 0 |
| Network | 4x 1GbE | 4 x 1GbE RJ-45 |
| 10GbE | no | optional |
| Max raw capacity | 168TB | 24 drives |
| Hot-swap | yes | yes |
| Form factor | 2U | Rackmount 2U |
| Released | 2016 | 2021 |