Hard drives still offer the largest storage capacity per pound, which is why they’re used in every type of system, including desktops, externals, NAS boxes and servers. However, they have one weakness that the alternatives do not: mechanical parts that wear out with time. Below we give you an honest evaluation of the advantages and disadvantages, which drives are the most reliable, and how the main drawback affects your data.
A hard drive’s main advantages are high capacity for the money and long retention of data in cold storage. The corresponding drawback is its internal moving parts (the spinning platters and heads), which will eventually fail through wear and tear. The upside for your data: when a hard drive dies, the files are usually still physically there, unlike with a failed SSD.
Data on a hard drive is stored magnetically on stacked, rotating platters, read and written by heads floating a fraction of a hair’s width above the surface on a cushion of air. This is very precise, mature technology, and it accounts for both the drive’s strengths and its one real weakness. The platters provide enormous amounts of storage at a relatively low price, but the moving parts are what eventually wear out. Most aspects of working with a hard drive follow directly from this trade-off.
What the hard drive has going for it above all is how much space you get for your money: nothing else comes close in terms of pounds per terabyte. That’s why large desktop, NAS and server storage continues to use spinning disk. Hard drives also hold data well when turned off: a shelved drive keeps its contents for years, where an unpowered SSD can slowly lose its charge. This makes them ideal for archives and backups. And, importantly, when they fail they usually fail mechanically, with the data still intact on the platters, so a failed hard drive can normally be recovered.
On the other hand, those platters and heads wear out, and they are sensitive to impact: a sudden jolt while the drive is spinning can send a head crashing into the surface. Compared to SSDs, hard drives are also much slower, and both heat and vibration affect them. The primary disadvantage is very clear: a hard drive has a limited service life and will eventually fail; the only unknown is whether you have a backup when it does. Signs that a drive may be nearing failure include clicking or grinding, slower transfers, freezes, files that vanish, and SMART warnings.
While there isn’t a single “most reliable hard drive”, enterprise and NAS-grade drives (such as WD Red, Seagate IronWolf and HGST Ultrastar) are designed to run around the clock and typically outlast budget desktop drives. Large published studies of failure rates support this, though every model has good and bad batches. In all honesty: buy for your workload, expect any drive to fail eventually, and back up your data onto separate hardware. What reliability provides is time, not immunity, and it tells you nothing about an SSD, which fails differently and is often harder to recover.
Capacity for the money is most important: hard drives store far more information per pound than SSDs, which is why big desktop, NAS and server storage still uses spinning disks. Hard drives also retain stored information without power, so they are useful for archiving, and when they fail, they usually fail mechanically, with the information still on the platters, so it can be recovered.
The moving parts. The platters and heads wear out over time, and dropping a drive while it is spinning can cause catastrophic damage, so every hard drive has a service life and will eventually fail. Hard drives are also slow compared to SSDs, and sensitive to heat and vibration. In practice, you need a backup, since failure is inevitable: the only question is when.
There’s no single answer. Enterprise and NAS-grade drives (WD Red, Seagate IronWolf, HGST Ultrastar and similar) are designed to run continuously, and as such they generally last longer than budget desktop drives. Large studies comparing failure rates support that, with variation between batches. Whatever you buy, keep a backup on separate hardware: reliability buys you a little extra time, not immunity from failure.
It really depends on how you intend to use each type of drive. SSDs are significantly faster and shock-resistant, so they are best suited to the drive you rely on day to day. Hard drives are less expensive per terabyte and ideal for bulk storage and archiving, and when they do fail, their data is more often recoverable than a failed SSD’s. Many people use an SSD for their operating system and a hard drive for storing and backing up files.
Typically, a hard drive in regular use lasts three to five years, though many last longer and some fail prematurely. The actual lifespan of your particular drive depends on several variables, including the model, how hard it’s worked, heat, and plain old luck of the batch. Since nobody can predict exactly when a drive will fail, it is wise to watch for warning signs (clicking, sluggish operation, SMART errors) and keep a recent backup, so a failure is an inconvenience rather than a loss.
The major downside of a hard drive is its moving parts, which eventually wear out, and that is exactly what data recovery is for. If yours is clicking, slow or not mounting, send it in and we’ll image it read-only and get your files back. Free diagnostic, then a fixed quote before any work.