Hard Drives: Explained

What is a hard drive?

Let’s imagine your computer as an office. The person at the desk is the CPU, and they’re doing all the work, all the thinking. The desk they sit at is the RAM, and the bigger the desk, the more things they can work on at one time (that’s why more RAM is usually better for people who multitask). The file cabinet, where they store all the things they’ve done and all the things they’re not working on at the moment, is the hard disk drive, or HDD.

The insides of a mechanical drive

The basic principles of hard drive technology haven’t changed much in the past 50 years: a smooth platter coated with magnetic particles spins at high speeds, and an armature with a read/write head attached writes and erases data. The big changes have been in size and speed: today’s most common drives spin at 7,200 RPM or 5,400 RPM, faster than your car at redline; and the read/write head moves at speeds faster than your eye can see. While the first hard drives stored only 5 MB of data, most common drives these days store 200,000x that much – 1TB or more, and as much as 20TB on some newer models!

A hard drive can only last so long, what with all those fast-moving, precision, highly sensitive parts. A typical consumer model lasts about five to seven years, or about 25,000 total power-on hours, before degradation starts to noticeably kick in. There are some high-quality, expensive, desktop-sized (3.5″ width) drives that are designed to stand up to longer, continuous use, but these are rare to see outside of certain business applications. The most inexpensive laptop-sized drives seem to have much shorter lifespans, frequently exhibiting issues in 10,000 hours or less. We’ve also noticed that the newer the drive is, the less dependable it seems to be – we suspect a lot of this comes down to the increased areal density (bits per physical area) of newer drives and the increased delicateness as a result.

These drives are also sensitive to bumps, drops, and falls. If your computer is dropped while it’s on, chances are the hard drive is permanently damaged. Hard drive failure usually has a noticeable onset, with the computer gradually getting slower as it has difficulty seeking data. You may notice harsh or rhythmic clicking noises, or the computer may fail to boot or show a message like “operating system not found”. You may also see a warning message issued by the computer at startup or within the operating system. If you notice warning signs like this, you should get the hard drive replaced immediately! If you wait too long, you run the risk of losing your data permanently.

Options for everybody

There’s two* major types of “hard drive”, each with different advantages and disadvantages. In this section, we’ll attempt to explain the different technologies and how they work, so that you can make an informed decision when it comes time to replace your existing drive.

A traditional mechanical drive

Mechanical Hard Drives (HDDs) use traditional spinning-platter technology and provide mass storage at low prices. You’ll usually pay $0.016-$0.04 per gigabyte of storage (retail). The advantage of a mechanical drive is that it is crazy cheap, even for large sizes.

The list of disadvantages is rather long, however: having motors, they can be hard on battery life. As mentioned before, they are extremely sensitive to bumps and drops. And they’re comparatively slow. Even a 7,200 RPM drive can only move so fast, and modern technology has drastically outpaced this old tech. While HDDs still have their place (primarily for large mass storage needs), there are far better options out there – and modern versions of operating systems such as Windows and MacOS more or less expect you to be using this modern technology.



Typical SATA solid state drives

Solid-State Drives (SSDs) are the speed demons of the storage world. There are no moving parts in an SSD, they rely solely on flash storage chips. As such, they are insanely fast at all times, and they are far easier on battery life than either of the above options. Over the last two decades, they’ve grown far more reliable than their ancestors, and can stand up to so many read/write cycles that their lifespan is better than most mechanical drives, assuming moderate, normal usage. To top off the list of advantages, they’re not sensitive to bumps and drops in the way that mechanical drives are (though dropping any electronic device is bad for it!)

An NVMe (2280 size) SSD

They are, however, more expensive than mechanical drives – but prices are falling all the time! Some of the best SSDs in the world run about $0.07 per gigabyte (retail). That can add up, though, so some people opt for smaller SSDs than they would choose for a traditional HDD. That may not be as big a problem as you fear, though. While the handful of new PCs that ship with mechanical hard drives (thankfully a dwindling number) use 1-2TB drives, the fact is that most common users will consume less than 200 GB storage in the entire lifespan of their computers, so you probably don’t really need all that space! If you really do (for example, if you do tons of video editing or downloading), and if you have a desktop computer, you may be able to use an SSD and an HDD together – a smaller SSD for your OS and all your programs, and a large HDD for all the stuff you store.

We currently recommend SK Hynix, Samsung, Sabrent, and Crucial SSDs as the best combination of affordability and high reliability and performance.

*There’s also a third type; “SSHDs”, but they’re extremely unreliable and very uncommon these days.

Upgrades, replacements, repairs

If you need help, we’re here for you. We can help you upgrade to a faster or larger drive, replace an ailing drive, or, in some cases, do data recovery from failing HDDs. When a drive has failed beyond our ability to recover, a clean room and specialized equipment are required, and we confidently recommend a number of providers including DataSavers in Atlanta, GA; and DriveSavers in California.

We try to keep SSDs in stock in common sizes, and we can special order a larger drive or HDD for you. SSD upgrades start at as little as $155, and if you bring your computer by the shop, we can assess your needs and your device’s age and condition, make recommendations, and provide a quote.