What does it do? (3 of 4) Part 3 - Hard Drive

So in part 1 we discussed the CPU and how it processes billions of calculations per second.

In Part 2 we spoke of the RAM, a temporary storage area that was fast access for those calculations and information.

In this part we're discussing the role of the Hard Drive.  The Hard Drive is a mass storage area for data, and is written in a form that will remain while your computer is switched off, making it available for the next time you turn on your computer.  This data can be in a large variety of formats.  Typically the kind of things you'd store on your hard drive are things like:-

Word Processor Documents
Spreadsheets
Presentations
Photos
Music
Video
Programs
Emails
Games & Other Applications
etc..

We mentioned in Part 2 that 1 GB could hold about the same amount of information as 20 volumes of encyclopedia's.  Hard Drives are vastly bigger than RAM, and it's not uncommon to see 500GB drives installed in most machines nowadays.  So, that's about 10,000 Encyclopedia Volumes inside your computer tower. Rather large. Drives are continually getting bigger, and we're now experiencing very low cost TB drives (Terrabyte is 1000 GB).

As much as a Hard Drive is fast, it's never as quick as RAM, and so if you have a small amount of RAM installed (a small desk in our illustration in Part 2) and the computer needs to write some information away, it will write that information into an area on the Hard Drive.  This process of writing data away to the Hard Drive is the delay that you experience when your computer starts to run slower. 

Other formats of drives are becoming available, Solid State Drives use the same technology as USB Sticks and are gradually becoming larger in size, but the cost and size limitations are still in early days.  Hybrid drives are also becoming popular, which contain the speed of a Solid State Drive, but have a Regular Hard Drive attached on the end for mass storage.

The size of Hard Drive that you require will largely depend on the type of files you plan to store.  If it's word processing documents that you're dealing with, you'll find 250 - 500GB Drives offer a good starting point, whereas if your dealing with Video footage or Music, you might find the need to increase your Hard Drive storage quickly.

There are optional configurations that you can use on your hard drives, but we'll cover that in depth discussion another time.