Side-by-side specifications of the Synology FS3420 and FS3600, from official datasheets. Differences are highlighted.
| FS3420 | FS3600 | |
| CPU | Intel Xeon D-1739 | Intel Xeon D-1567 |
| Cores / threads | 8 cores / 16 threads | 12 cores / 24 threads |
| RAM (base) | 32 GB DDR4 ECC RDIMM | 16 GB DDR4 ECC RDIMM |
| RAM (max) | 192 GB | 128 GB |
| Drive bays | 24 × 2.5-inch SATA SSD | 24 |
| Expandable to | 0 | 72 |
| M.2 slots | 0 | 0 |
| Network | 2 × 10GbE RJ-45 | 4×1GbE RJ-45, 2×10GbE RJ-45 |
| 10GbE | yes | yes |
| Max raw capacity | 1 PB | 92.16 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2026 | 2017 |
| Power consumption | 122.0 W / unknown | 258.23 W / 127.99 W |
| DSM at launch | — | 6.1 |
Choose the FS3600 if you need a stronger CPU, much higher RAM ceiling, more drive bays/expansion, and built-in 10GbE; it’s the more scalable platform for heavier workloads. Choose the FS3420 if you want a smaller, simpler box with lower upfront cost and don’t need as much growth headroom. Neither model is a good fit if you specifically need M.2 cache slots, since that’s not a decisive advantage here.