Last year Western Digital launch the Red series of hard disks intended for use in NAS devices. Seagate also has such a series now called the Seagate NAS HDDs. We tested the 4TB model and compared it to Western Digital's disks.
It's more than a marketing gimmick, special NAS hard drives. They have different software features and go through more rigid certification and compatibility tests. Seagate basically does the same with its NAS disks as Western Digital does for its Red disks.
Seagate's special firmware, called NASworks, features TLER which stands for Time-Limited Error Recovery. What it means is that when a disk is unable to read a certain piece of data it will give up quicker and after 7 seconds tell the controller there's a read error. This is important for a NAS, because if a disk gets stuck attempting to read data and therefore becomes unresponsive, it will be removed from the RAID array. With TLER enable the NAS can retrieve the necessary data from another disks and alert the user there's a problem with the disk.
A second difference between normal disks and NAS disks is that they're supposed to generate less vibration when more than one are used in the same chassis. Seagate says it's a hardware-based solution provided by further balancing the motor inside the disk. This decreases noise levels and improves the lifespan of the disk.
NAS disks are also configured differently in terms of power management in the firmware. According to Seagate the firmware is optimised for energy efficiency but also to wake up from sleep mode as quickly as possible.
NAS disks are tested for compatibility with different NAS devices. On its website, Seagate has an impressive list of devices the disks have been tested with, and it includes most popular NAS devices.
The Seagate NAS HDD disks come in three capacities: 2TB, 3TB and 4TB. The 3.5-inch disks have the Serial ATA 600 interface, spin at 5900 rpm and contain 64 MB of cache. 1 TB platters are used, so the 4 TB model we tested has four platters.
The Seagate NAS HDD 4TB costs an average of £150 / €181, which is almost exactly the same as the price of the main competitor: the Western Digital Red 4TB. It's not that much more expensive than Seagate's own Desktop HDD.14 4TB.