Side-by-side specifications of the Synology DS1019+ and DS1511+, from official datasheets. Differences are highlighted.
| DS1019+ | DS1511+ | |
| CPU | Intel Celeron J3455 | 1.8GHz dual-core |
| Cores / threads | 4 cores / 4 threads | 2 cores / 2 threads |
| RAM (base) | 8 GB DDR3L non-ECC | 1GB |
| RAM (max) | 8 GB | 3GB |
| Drive bays | 5 | 5 |
| Expandable to | 5 | 10 (2× DX510) |
| M.2 slots | 2 M.2 2280 NVMe | 0 |
| Network | 2 x 1GbE RJ-45 | 2× Gigabit |
| 10GbE | no | no |
| Max raw capacity | 60 TB internal raw; 10 drives with DX517 | 15TB |
| Hot-swap | yes | yes |
| Form factor | Desktop | desktop |
| Released | 2019 | 2011 |
| Power consumption | 38.59 W / 13.32 W | 68 W / 30 W |
| DSM at launch | — | — |
Pick the DS1019+ unless you specifically need the DS1511+’s older 5-bay platform for legacy reasons: the DS1019+ has the newer, much faster Intel Celeron CPU, a higher RAM ceiling, and 4 built-in M.2 slots for SSD cache. The DS1511+ is the weaker choice on CPU/RAM and has no 10GbE or M.2 support; if you need more than 5 bays on the DS1019+, you can expand it with a DX517.