Side-by-side specifications of the Synology DS419SLIM and DS420+, from official datasheets. Differences are highlighted.
| DS419SLIM | DS420+ | |
| CPU | Marvell Armada 385 88F6820 | Intel Celeron J4025 |
| Cores / threads | 2-core | 2 cores, 2 threads |
| RAM (base) | 512 MB | 2 GB DDR4 |
| RAM (max) | 512 MB | 6 GB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 2 |
| Network | 2x 1GbE RJ-45 | 2x GbE RJ-45 |
| 10GbE | no | no |
| Max raw capacity | 20 TB | 64 TB |
| Hot-swap | yes | yes |
| Form factor | mini cube | desktop |
| Released | 2019 | 2020 |
Choose the DS420+ unless you specifically need the tiny 2.5-inch form factor of the DS419slim. The DS420+ is much stronger: Intel Celeron CPU, 2 GB RAM with a higher ceiling, 4 bays, optional 10GbE via expansion, and M.2 NVMe slots; the DS419slim has a weaker ARM-class CPU, lower RAM ceiling, 4 slim bays, no 10GbE, and no M.2.