Side-by-side specifications of the Synology DS418play and DS419SLIM, from official datasheets. Differences are highlighted.
| DS418play | DS419SLIM | |
| CPU | Intel Celeron J3355 | Marvell Armada 385 88F6820 |
| Cores / threads | 2/2 | 2-core |
| RAM (base) | 2 GB | 512 MB |
| RAM (max) | 6 GB | 512 MB |
| Drive bays | 4 | 4 |
| Expandable to | 0 | 0 |
| M.2 slots | 0 | 0 |
| Network | 2x 1GbE | 2x 1GbE RJ-45 |
| 10GbE | no | no |
| Max raw capacity | 40 TB | 20 TB |
| Hot-swap | yes | yes |
| Form factor | desktop | mini cube |
| Released | 2017 | 2019 |
Pick the DS418play if you want more headroom: it has a much stronger Intel Celeron CPU, higher RAM ceiling, and 4 bays with support for expansion, so it’s the safer choice for larger files, more users, and growth. The DS419slim is the tiny/quiet option with a weaker ARM CPU, lower RAM ceiling, and only 2.5" bays, but neither model has 10GbE or M.2.