The Hard Disk Drive (HDD) is where all the data in a computer is stored when it’s not in use by the processor. Dissimilar to memory, data stored on a HDD remains complete when the computer is turned off. All the programs, documents, photos, videos and music that you keep on your computer are stored on the HDD and encumbered into memory when you begin using them.

When it comes to choosing a hard drive it is relatively simple and is usually based of 2 factors; these are the size and speed. The size of the drive you choose will be principally based on your personal needs, but for most people a drive not less than 250GB is a good starting point.

The speed is made up of several factors, rotations per minute, cache and connection type. Nevertheless for the vast majority of people a 7200rpm drive that connects via a SATA port will be the best option, leaving you simple to decide on the amount of cache you need (8MB, 16MB or 32MB). As explained below you will see very little difference in terms of performance once above 16MB.

If you are building a very high performance PC you may want to consider 10000rpm drives, though the price to performance level is relatively low. Another option is a SSD (Solid State Drive) which offer amazingly fast boot up speeds and are often 10X faster than a typical HDD. You may also consider RAID as a way of refining either performance or reliability of your storage. If you have the budget for it, RAID can also provide both reliability and performance improvements on the same storage.