Side-by-side specifications of the Synology FS3420 and FS6420, from official datasheets. Differences are highlighted.
| FS3420 | FS6420 | |
| CPU | Intel Xeon D-1739 | AMD EPYC 7303 |
| Cores / threads | 8 cores / 16 threads | 16 cores / 32 threads |
| RAM (base) | 32 GB DDR4 ECC RDIMM | 64 GB DDR4 ECC RDIMM |
| RAM (max) | 192 GB | 1024 GB |
| Drive bays | 24 × 2.5-inch SATA SSD | 24 |
| Expandable to | 0 | — |
| M.2 slots | 0 | — |
| Network | 2 × 10GbE RJ-45 | 2 × 10GbE RJ-45 |
| 10GbE | yes | yes |
| Max raw capacity | 1 PB | 1 PB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2026 | 2026 |
| Power consumption | 122.0 W / unknown | 164.74 W / unknown |
| DSM at launch | — | — |