Side-by-side specifications of the Synology RS2418+ and RS2418RP+, from official datasheets. Differences are highlighted.
| RS2418+ | RS2418RP+ | |
| CPU | Intel Atom C3538 | Intel Atom C3538 |
| Cores / threads | 4 cores / 4 threads | 4 cores / 4 threads |
| RAM (base) | 4 GB DDR4 non-ECC UDIMM | 4 GB DDR4 non-ECC UDIMM |
| RAM (max) | 64 GB | 64 GB |
| Drive bays | 12 | 12 |
| Expandable to | 12 (up to 24 total with RX1217/RX1217RP) | 12 |
| M.2 slots | 0; optional M.2 SATA adapter card | 0 (via optional adapter card) |
| Network | 4 x 1GbE RJ-45 | 4 x 1GbE RJ-45 |
| 10GbE | optional | optional |
| Max raw capacity | 144 TB internal; 288 TB with 1 expansion unit | 288 TB |
| Hot-swap | yes | yes |
| Form factor | 2U rackmount | 2U rackmount |
| Released | 2018 | 2018 |
| Power consumption | 109 W / 52.4 W | 119.6 W / 55.9 W |
| DSM at launch | 6.2 | 6.2 |
Choose the RS2418RP+ only if you want redundant power supplies; otherwise, the RS2418+ is the same core platform for less money. Both use the same CPU, have the same 4GB RAM with a 64GB ceiling, 12 bays via 2 expansion units, and both support 10GbE and M.2 NVMe caching through add-ons. If redundancy does not matter, buy the RS2418+.