Side-by-side specifications of the Synology DS420j and DS425+, from official datasheets. Differences are highlighted.
| DS420j | DS425+ | |
| CPU | Realtek RTD1296 | Intel Celeron J4125 |
| Cores / threads | 4-core | 4/4 |
| RAM (base) | 1 GB DDR4 | 2 GB |
| RAM (max) | 1 GB | 6 GB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 2 |
| Network | 1 x 1GbE RJ-45 | 1x1GbE + 1x2.5GbE |
| 10GbE | no | no |
| Max raw capacity | 64 TB | 108 TB |
| Hot-swap | no | yes |
| Form factor | desktop | desktop |
| Released | 2023 | 2025 |