Side-by-side specifications of the Synology DS918+ and DS920+, from official datasheets. Differences are highlighted.
| DS918+ | DS920+ | |
| CPU | Intel Celeron J3455 | Intel Celeron J4125 |
| Cores / threads | 4-core | 4 cores / 4 threads |
| RAM (base) | 4 GB DDR3L | 4 GB DDR4 |
| RAM (max) | 8 GB | 8 GB |
| Drive bays | 4 | 4 |
| Expandable to | 9 | 9 |
| M.2 slots | 2 | 2 |
| Network | 2 x 1GbE | 2x 1GbE RJ-45 |
| 10GbE | no | no |
| Max raw capacity | 40 TB | 64 TB |
| Hot-swap | yes | yes |
| Form factor | desktop | desktop |
| Released | 2018 | 2020 |
Choose the DS920+ unless it’s much more expensive: it has a faster Intel Celeron J4125 CPU, supports up to 8 GB RAM, and keeps the same 4-bay design with expansion support. It also adds two M.2 NVMe slots for SSD cache; neither model has built-in 10GbE, and both can use an expansion unit for more bays.