Side-by-side specifications of the Synology RS1219+ and RS1221+, from official datasheets. Differences are highlighted.
| RS1219+ | RS1221+ | |
| CPU | Intel Atom C2538, 2.4 GHz | AMD Ryzen V1500B |
| Cores / threads | 4 cores / 4 threads | 4 cores / 8 threads |
| RAM (base) | 2 GB DDR3L non-ECC SODIMM | 4 GB DDR4 ECC SODIMM |
| RAM (max) | 16 GB | 32 GB |
| Drive bays | 8 | 8 |
| Expandable to | 12 total with RX418 | 12 total with RX418 |
| M.2 slots | 2 via optional M2D18 adapter; SATA only | 0 built-in; optional adapter card |
| Network | 4 x 1GbE RJ-45 | 4 × 1GbE RJ-45 |
| 10GbE | optional | optional |
| Max raw capacity | 144 TB with RX418 | 108 TB single volume |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2018 | 2021 |
| Power consumption | 60.31 W / 29.04 W | 49.89 W / 22.64 W |
| DSM at launch | — | — |
Choose the RS1221+ for its faster AMD Ryzen V1500B CPU, 32GB maximum RAM versus the RS1219+’s Intel Atom C2538 and 8GB, plus built-in M.2 NVMe slots. Both are 8-bay units with similar expansion options, but neither includes 10GbE; add a compatible PCIe 10GbE card if needed.