Side-by-side specifications of the Synology DS414slim and DS415+, from official datasheets. Differences are highlighted.
| DS414slim | DS415+ | |
| CPU | Marvell Armada 370 | Intel Atom C2538 |
| Cores / threads | 1/1 | 4C/4T |
| RAM (base) | 512 MB | 2 GB |
| RAM (max) | 512 MB | 6 GB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 0 |
| Network | 2x Gigabit | 2x Gigabit |
| 10GbE | no | no |
| Max raw capacity | 6 TB | 24 TB |
| Hot-swap | yes | yes |
| Form factor | 2.5-inch SATA NAS | desktop |
| Released | 2014 | 2014 |
Choose the DS415+ if you care about performance and headroom: it has a much stronger CPU and a higher RAM ceiling, plus 4 bays versus the DS414slim’s 4 slim bays but no real expansion advantage. It also supports 10GbE via add-on and M.2 SSD caching via the appropriate expansion, while the DS414slim does not. Pick the DS414slim only if compact size and lower power matter more than speed or upgradeability.