Side-by-side specifications of the Synology DS718+ and DS720+, from official datasheets. Differences are highlighted.
| DS718+ | DS720+ | |
| CPU | Intel Celeron J3455 | Intel Celeron J4125 |
| Cores / threads | 4-core | 4 cores |
| RAM (base) | 2 GB | 2 GB DDR4 |
| RAM (max) | 6 GB | 6 GB |
| Drive bays | 2 | 2 |
| Expandable to | 7 | 7 |
| M.2 slots | 0 | 2 |
| Network | 2x 1GbE | 2 x GbE RJ-45 |
| 10GbE | no | no |
| Max raw capacity | 20 TB | 32 TB |
| Hot-swap | yes | yes |
| Form factor | desktop | desktop |
| Released | 2017 | 2020 |
Choose the DS720+ if you want the newer Celeron J4125 CPU, a higher RAM ceiling of 6GB vs the DS718+’s 2GB, and built-in M.2 NVMe slots for SSD cache. Both are 2-bay NAS units, but neither has built-in 10GbE, and neither is the one to buy if you need expansion beyond two bays.