| CPU | AMD R-Series RX-421ND 4-core 2.1 GHz processor, Turbo Core to 3.4 GHz |
| CPU Architecture | 64-bit x86 |
| Floating Point Unit | |
| Encryption Engine | (AES-NI) |
| System Memory | 16 GB UDIMM DDR4 (2 x 8 GB) |
| Maximum Memory | 64 GB (4 x 16 GB) |
| Memory Slot | 4 x U-DIMM DDR4 For dual- or quad-DIMM configurations, you must use a pair of identical DDR4 modules. |
| Flash Memory | 512 MB (Dual boot OS protection) |
| Drive Bay | 8 x 3.5-inch SATA 6Gb/s, 3Gb/s The system is shipped without HDD. For the HDD compatibility list, please visit https://www.qnap.com/compatibility/ |
| Drive Compatibility | 3.5-inch SATA hard disk drives 2.5-inch SATA hard disk drives 2.5-inch SATA solid state drives |
| Hot-swappable | |
| M.2 Slot | 2 x M.2 2280 SATA 6Gb/s slots The M.2 SSD is not included as standard. M.2 SSD operations can easily generate excessive heat. It is recommended to install a heatsink (from QNAP or a third-party provider) on the M.2 SSD. |
| SSD Cache Acceleration Support | |
| Gigabit Ethernet Port (RJ45) | 4 Expandable with an optional PCIe adapter |
| 10 Gigabit Ethernet Port | 2 x 10GbE SFP+ Pre-installed with a PCIe adapter |
| Wake on LAN (WOL) | |
| Jumbo Frame | |
| PCIe Slot | 1 Slot 1: PCIe Gen 3 x4 Pre-installed with a 10GbE adapter |
| USB 2.0 port | 4 |
| USB 3.2 Gen 1 port | 2 |
| USB 3.2 Gen 2 (10Gbps) Port | Optional via a PCIe adapter |
| Form Factor | 2U Rackmount |
| LED Indicators | HDD 1-8, Status, LAN, USB, Power |
| Buttons | Power, Reset |
| Dimensions (HxWxD) | 3.5 × 18.98 × 21.02 inch |
| Weight (Net) | 24.91 lbs |
| Operating Temperature | 0 - 40 °C (32°F - 104°F) |
| Storage Temperature | -20 - 70°C (-4°F - 158°F) |
| Relative Humidity | 5-95% RH non-condensing, wet bulb: 27˚C (80.6˚F) |
| Power Supply Unit | 250W (x2) PSU, 100 - 240V |
| Power Consumption: HDD Sleep Mode | 46.9 W |
| Power Consumption: Operating Mode, Typical | 107.65 W Tested fully populated with WD10EFRX hard drives. |
| Fan | 2 x 70mm, 12 VDC |
| Other Interfaces | 1 x 3.5mm console port |
| System Warning | Buzzer |
| Standard Warranty | 3 |
| Max. Number of Concurrent Connections (CIFS) - with Max. Memory | 1200 |