Today’s SOHO-class Network Attached Storage devices are mostly designed for hard disk drives of the 3.5-inch form-factor. Such HDDs are rather inexpensive and have a large storage capacity (up to 2 terabytes), and some of them feature reduced power consumption and noise. A NAS does not present any special requirements to the speed of the hard disk. Considering the rather low speed of the platform and network interface, even the slowest of HDDs will not affect the speed of the client’s access to files.
However, the general trend towards miniaturization has reached NASes as well and 2.5-inch hard disk drives, usually found in notebooks, are now considered appropriate for NASes. Such HDDs consume less power and produce less heat than their larger counterparts but have somewhat lower speed characteristics. They are also more expensive and are inferior to 3.5-inchers in terms of maximum storage capacity, which is currently limited to only 500 gigabytes. Thus, it would take four or more disks to build a NAS comparable in capacity to a simple single-disk classic NAS. On the other hand, four disks make it possible to organize a fault-tolerant RAID5 array with a useful capacity of 75% from the total of its disks.
This solution is available from Synology, a leading developer of NAS products. The new DS409slim model can accommodate four 2.5-inch HDDs while measuring only 14 x 10.5 x 12 centimeters which is smaller than the size of typical NASes for two 3.5-inch disks. Let’s check out the other parameters of this solution right now.