What’s an SSD?
Posted: 30th Jan 2012
If you’ve been looking at new laptops or PCs lately, there’s every chance you may have come across the acronym ‘SSD’ in the system specifications of machines you’ve been thinking about buying. But what is an SSD, and do you need one?
The letters SSD stand for Solid State Drive, and it’s a relatively new type of hard disk which is much faster than traditional ones. Open up a normal hard disk, and inside you find several small circular platters which store information when a magnetic needle passes over an area of the surface. Like an old LP, the platters spin underneath the needle, which can both read and write data.
Platters in a traditional hard drive move very quickly, at up to 7200 revolutions per minute. They have to be manufactured to very precise specifications, and can be relatively easily damaged, causing you to lose valuable information.
A Solid State Drive, as the name suggests, has no moving parts inside. Instead, an SSD works more like a camera memory card, using silicon chips rather than magnetic discs, as storage. Because there are no moving parts, they’re very tough – perfect for laptops and tablets – but they’re also capable of saving and recalling data much faster than a mechanical drive.
A computer with an SSD will be able to load files off of the drive very quickly, reducing the time it takes to boot a PC from off and start programs when you click on their icon.
The drawback of SSDs is that they are very expensive to manufacture, and they have much less capacity. Right now, a 120GB SSD costs much more than a traditional hard drive with almost ten times as much space on board. For storing lots of music or movie files, or installing more than a few games, you’ll want a large hard drive even if it’s slightly slower.
As a result, many laptops and PCs now come with both a small SSD and a hard drive installed. In this case, the SSD is used for storing only those files that Windows has to access on a regular basis, where its speed can be used to best effect. This is a process known as ‘caching’, so you’ll sometimes see an SSD installed in that configuration described as a ‘cache drive’.
Don’t worry, though, operating the PC will still be as simple as normal. Windows will work out which files are best kept on the SSD for you, so you won’t have to do anything to reap the benefits.

