How NAS and Surveillance Drives Differentiates From Desktop HDDs

NAS and surveillance HDDs are designed and tested to deliver reliable, long-term 24x7 operation. The drives in most desktop and laptop computers aren't built with this type of usage in mind.

Moreover, NAS HDDs and surveillance HDDs, typically incorporate rotational vibration (RV) sensors. These enable multiple drives to be safely mounted close together in the same enclosure, and still operate reliably. Without the sensors, there's a risk of rotational vibration affecting other drives in a multi-bay system.

Like NAS and surveillance HDDs, server-grade HDDs are designed for 24x7 operation and for systems where multiple disks operate in close proximity. The key difference is around data workloads: server HDDs are built for the high-volume work associated with large numbers of users and intensively used production databases. NAS and surveillance HDDs are engineered for the less-demanding workloads typical of surveillance or central network storage.

The cost of SSDs has come down considerably, and indeed some high-end NAS systems use them for caching. SSDs are all about performance, but spinning-disk HDDs still have the upper hand when it comes to providing large amounts of capacity in an economical way. And with lots of R&D, particularly to increase the data density and number of platter is going on around HDDs, we should see the cost/GB continue to fall and significant increases in capacity. As a result, they'll remain an essential part of the storage ecosystem for at least the next 10 years.

We've recently seen improvements to the way data is recorded and to the number of platters you can fit into the standard 3.5-inch form factor. Both these enhancements mean you can now get NAS-grade drives with capacities up to 8TB. The next steps could be to bring the helium-filled disks - which you can already find in some server-grade applications - to NAS systems. This enables the platters to be thinner, meaning you can fit more of them into the same size of enclosure. This development should see NAS drive capacities boosted to around 14TB. There's also work going on in the HDD industry to develop new recording technologies, which should see NAS HDD capacities edge towards and eventually break through the 40TB capacity barrier.