Side-by-side specifications of the Synology DS223 and DS223j, from official datasheets. Differences are highlighted.
| DS223 | DS223j | |
| CPU | Realtek RTD1619B | Realtek RTD1619B |
| Cores / threads | 4/4 | 4/4 |
| RAM (base) | 2 GB DDR4 non-ECC | 1 GB DDR4 |
| RAM (max) | 2 GB | 1 GB |
| Drive bays | 2 | 2 |
| Expandable to | 0 | — |
| M.2 slots | 0 | 0 |
| Network | 1x 1GbE | 1x 1GbE |
| 10GbE | no | no |
| Max raw capacity | 108 TB | 108 TB |
| Hot-swap | yes | no |
| Form factor | 2-bay desktop NAS | desktop |
| Released | 2026 | 2023 |
Pick the DS223 if you want the stronger CPU and more RAM headroom: the DS223 has a quad-core Realtek RTD1619B and 2 GB RAM, while the DS223j uses a weaker dual-core Realtek RTD1619B/RTD1296-class J-series chip with 1 GB RAM. Both are 2-bay, non-expandable NAS units with no 10GbE and no M.2 slots, so the DS223 is the better choice for heavier SMB use; the DS223j is fine for basic backups and light home file sharing.