QNAP TS-431U Diskless System Affordable Rack-Optimized 4-Bay 1U NAS Port RJ-45: 2 x 10/100/1000M Port USB: 4 x USB 3.0 ports (rear) 1 x USB 2.0 port (front) Support USB printer, pen drive, and USB UPS etc. HDD Interface: 4 x 3.5 or 2.5 SATA 6 Gb/s, SATA 3 Gb/s hard drive or SSD Form Factor: 1U Processor: Freescale ARM Cortex-A9 dual-core 1.2 GHz processor with hardware encryption engine Default/ Max. Memory: 512MB LEDs: Status, LAN, USB, HDD 1-4 Power: Power Consumption (W) HDD standby: 19.3W Typical operation: 34.9W (with 4 x 2 TB HDDs installed) Power Supply Input: 100-240V AC, 50 / 60Hz; Output: 250W