Scalable quad core 5 bay storage solution outstanding reading throughput over 436 mbs and writing throughput over 449 mbs encrypted throughput over 334 mbs in reading and 269 mbs in writing four gigabit rj 45 ports with failover and link aggregation support scalable up to 15 drives with two dx517 expansion units synology high availability sha allows for uninterrupted services with seamless transitioning between clustered servers synology diskstation ds1517 comes with a quad core cpu ha