Side-by-side specifications of the Synology RS2421RP+ and RS2423RP+, from official datasheets. Differences are highlighted.
| RS2421RP+ | RS2423RP+ | |
| CPU | AMD Ryzen V1500B | AMD Ryzen V1780B |
| Cores / threads | 4-core/4-thread | 4/8 |
| RAM (base) | 4 GB | 8 GB |
| RAM (max) | 32 GB | 32 GB |
| Drive bays | 12 | 12 |
| Expandable to | 24 | 24 |
| M.2 slots | optional via adapter | 0 |
| Network | 4 x 1GbE RJ-45 | 2x 1GbE + 1x 10GbE |
| 10GbE | optional | yes |
| Max raw capacity | 108 TB per volume | 200 TB |
| Hot-swap | yes | yes |
| Form factor | Rackmount 2U | 2U rack |
| Released | 2021 | 2023 |