The QNAP TS-459 Pro II Turbo NAS is the industrys true business-class network-attached storage designed with next-generation technology like 6 Gb/s (SATA III) hard drives support, delivering blazing fast data transfer rates. The NAS houses up to four hot-swappable 3.5-inch or 2.5-inch SATA hard disk drives for up to 12TB of networked storage (based on 3TB hard drives). The TS-459 Pro II incorporates the Intel Atom™ D525 1.8 G Hz dual core processor, capable of delivering ultra high performance, reliability, & lower power consumption during intensive data transfers. The TS-459 Pro II features 1GB of high performance DDRIII RAM, which can be upgraded to 3GB by simply adding a 2GB RAM in the additional RAM slot.