The N7700 Pro I have here is fitted with 7 x 2TB hard disks in RAID 5 formation which gives a single volume of 10.9TB of disk space, this means that I can hold large collections of images in one place which aids indexing and workflow.
The speed comes from its dual core processor which drives the controller and gigabit Ethernet to its full speed and so I can get real world transfer figures of 65mb/sec writes and even faster reads. This is over twice the speed of a USB2 drive connected directly to a host computer so its very impressive.
When dealing with large amounts of high res images this device would seem to be able to delivery speedy storage with the safety net of RAID 5 which means that if a disk fails I just need to swap it out for a new one (the image above shows the access door closed (left) and open (right) each disk is in a separate caddy.
The power supply to the device is a single point of failure however so its important I have at least one copy of every file on the device backed up somewhere else, as always, redundancy is the safety net.