Side-by-side specifications of the Synology FS3600 and FS6400, from official datasheets. Differences are highlighted.
| FS3600 | FS6400 | |
| CPU | Intel Xeon D-1567 | 2x Intel Xeon Silver 4110 |
| Cores / threads | 12/24 | 16c/32t |
| RAM (base) | 16 GB | 32 GB |
| RAM (max) | 128 GB | 512 GB |
| Drive bays | 24 | 24 |
| Expandable to | 72 | 72 |
| M.2 slots | 0 | 0 |
| Network | 4x1GbE, 2x10GbE | 2x 1GbE + 2x 10GbE RJ-45 |
| 10GbE | yes | yes |
| Max raw capacity | 92.16 TB | 184.32 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rack | rackmount |
| Released | 2026 | 2025 |
Choose the FS6400 if you need a much larger all-flash system: it uses dual Intel Xeon D-1541 CPUs, supports up to 512 GB RAM, has 24 bays with expansion support, and includes built-in 10GbE plus M.2 slots. The FS3600 is the smaller/cheaper option with a single Intel Xeon D-1567, up to 128 GB RAM, 24 bays but no expansion, and it also has built-in 10GbE and M.2. For most home/SMB buyers, the FS3600 is enough unless you need the FS6400’s extra CPU and memory headroom for heavier virtualization or more users.