The Hard Drive: What It Is, What It Does (Part 1 of a 2 Part Series)

by Geek Squad Agent on ‎04-23-2014 10:21 PM (62,472 Views)

The same can be said of computers. Most people use them, but few know how they work — which is fine. (More work for us!)

Through the many years Geek Squad Agents have helped fix and maintain computers for clients, we’ve found that a little basic computer knowledge helps people choose the right machine for their needs and keep it in top working condition. While most civilians don’t need to know a lot about Ethernet connections, motherboards or power supplies, knowing a little something about hard drives can be helpful.


With that in mind, we put together a two-part series on hard drives to help. In this first post, we’ll explain what hard drives are and give you a few basics on how they work. Our second post goes into what computer users need to know to keep their hard drives in good shape.


Data Storage

The hard drive is your computer’s data storage device. Most hard drives store data electromagnetically on a rotating  disk coated with a ferromagnetic film (quite a mouthful so far, ain’t it?). Data is written to and read from the disk by a read-write head. The disk stores all the information needed by your computer – the operating system, drivers, software programs and, of course, the data (pictures, music, documents) you create and keep on your machine.


Sound familiar? That’s right, the science of storing information on a rotating disk goes back to the early 1900’s with the gramophone and early record players. Eventually this technology expanded to more than just music. Although much smaller than an old school records, hard drives can store countless songs and information, making it possible to easily carry powerful data-processing machines and ushering in the age of mobile computing..


Hard drives have two basic characteristics that determine their functionality– their size (capacity) and the speed at which they can read and write data (performance). Knowing this is important when selecting a computer to meet your needs. If you need to store a lot of data or use many software programs, getting a computer with a large hard drive — measured in Gigabytes (GBs) or Terabytes (TBs) — is essential. Filling up a hard drive has a negative impact on a device’s performance (and their life span), so when buying a computer it’s important to get one with a hard drive that has plenty of room.


The performance of a hard drive (measured in RPMs and cache storage) will tell you how quickly the drive will be able to write or read data from it. If you use memory-heavy software, or create and manipulate complex files like videos, large graphics or music, a fast drive (with a lot of cache storage) will come in very handy.


Hard disks typically have two different RPM calibrations – 5400 RPMs (most often found in laptops, notebooks, and netbooks) and 7200 RPMS (usually found in desktop computers and servers). The 7200 RPM hard drives are slightly larger in physical size and require a little more power than the 5400 RPM types, but the faster spinning disk allows programs and files to load more quickly, making the whole computing experience a bit faster.


Solid-state Drives

Hard drive technology recently took a great leap forward with the introduction of reliable, more-affordable solid-state drives (SSDs). Unlike traditional hard drives, SSDs use a “flash memory” system (much like USB drives) to store data, eliminating the need for spinning disks and read-write heads. This new generation of SSDs are much more rugged than traditional hard drives and can access data more quickly that their spinning-disk cousins. But they are more expensive as well.  It’s likely to take some time for SSDs to become widely available in consumer-grade computers.


Now you know a little bit more about the hard drive, and what to look for in one that will fit your computing needs. Check out our next installment in this series soon, where we’ll talk a little bit more about how to take care of your hard drive, and protect yourself against hard drive failure. If you have concerns about your current hard drive, we have Agents standing by to help.

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