Side-by-side specifications of the Synology RS407 and RS408RP, from official datasheets. Differences are highlighted.
| RS407 | RS408RP | |
| CPU | 500 MHz | 800 MHz |
| Cores / threads | — | — |
| RAM (base) | 128 MB | 512 MB |
| RAM (max) | — | — |
| Drive bays | 4 | 4 |
| Expandable to | 0 | — |
| M.2 slots | 0 | 0 |
| Network | 1× Gigabit | 2× Gigabit |
| 10GbE | no | no |
| Max raw capacity | 4 TB | 4 TB |
| Hot-swap | yes | yes |
| Form factor | 1U rackmount | 1U rackmount |
| Released | — | — |
| Power consumption | 60 W / 21 W | 69.5 W / 25 W |
| DSM at launch | — | — |
Choose the RS408RP if you need a newer/faster platform: it has the better CPU, higher RAM ceiling, and more drive bays/expansion headroom than the RS407. Neither model is a fit if you specifically need built-in 10GbE or M.2, since those aren’t part of these units’ spec; for that, you’d be looking at a different Synology line. If your needs are basic file storage and you want the cheaper option, the RS407 is the simpler buy.