Side-by-side specifications of the Synology DS1618+ and DS1821+, from official datasheets. Differences are highlighted.
| DS1618+ | DS1821+ | |
| CPU | Intel Atom C3538 | AMD Ryzen V1500B |
| Cores / threads | 4-core | 4 |
| RAM (base) | 4 GB DDR4 | 4 GB |
| RAM (max) | 32 GB | 32 GB |
| Drive bays | 6 | 8 |
| Expandable to | 12 | 18 |
| M.2 slots | 2 | 2 |
| Network | 4 x 1GbE | 4x1GbE RJ-45 |
| 10GbE | optional | optional |
| Max raw capacity | 72 TB | 108 TB |
| Hot-swap | yes | yes |
| Form factor | desktop | desktop |
| Released | 2018 | 2020 |