The ability to expand to 6GB DDR3 RAM & scale storage up to 8 drives with Synology Expansion Unit RX415 give your business the agility to meet evolving workload demands. Contains the WD Red Pro HDD's NAS optimised for 19" rack mount solutions with multi Axis shock sensors, vibration protection & dual actuators. 4 GHz, RS815+/RS815RP+ delivers average 389. 03 MB/s reading & 361. 33 MB/s writing. Ideal encrypted data transmission with AES-NI RS815+/RS815RP+ features a hardware encryption engine, which offloads encryption calculation tasks away from the main CPU. That means files & folders are encrypted on the fly without compromising the performance delivering encrypted data transmission speeds over 388. 66 MB/s reading & 158. 9 MB/s writing. With a RX415 connected through an e SATA cable with specially-designed locking connectors, raw capacity can be as high as 48TB.