Side-by-side specifications of the Synology DS1511+ and DS1515, from official datasheets. Differences are highlighted.
| DS1511+ | DS1515 | |
| CPU | 1.8GHz dual-core | Annapurna Labs Alpine AL-514 |
| Cores / threads | 2 cores / 2 threads | 4 cores / 4 threads |
| RAM (base) | 1GB | 2 GB |
| RAM (max) | 3GB | 2 GB |
| Drive bays | 5 | 5 |
| Expandable to | 10 (2× DX510) | 15 |
| M.2 slots | 0 | 0 |
| Network | 2× Gigabit | 4 x 1GbE |
| 10GbE | no | no |
| Max raw capacity | 15TB | 40 TB |
| Hot-swap | yes | yes |
| Form factor | desktop | Desktop |
| Released | 2011 | 2015 |
| Power consumption | 68 W / 30 W | — |
| DSM at launch | — | — |