Hard drives: Features explained
The basics
An external hard drive is the equivalent of a filing cabinet for your PC data
Your pc computer or laptop's hard disk is a bit like a big filing cabinet.
It stores all your data – eg programs and files – even when your computer is turned off. The amount of data a hard drive can store is measured in bytes.
The files that are created when you save digital photos or home videos are much larger than the ones you get when you save a typical word processing document (an average digital photo is about 500 Kilobytes).
Capacity
Just as we've started to create larger and larger files, so the size of hard drives has ballooned. Whereas a few years ago an 80GB hard disk was felt to be ample, you can now get home PCS with hard disks of 500GB and higher.
Types of external hard drive
There are several different kinds of external hard disk.
Standalone
The ones that you're likely to be most familiar with are the standalone drives which attach to and sit alongside your computer.
Portable
However, you can also get portable hard disks. These are generally smaller than the standalone drives both in terms of physical size and capacity. These are ideal for transferring files between computers.
Another advantage of a portable drive is that it’s possible to keep your data separate from your computer. Most businesses back up their data and keep their backup off site.
Ideally, we should all do the same – keep a copy of important data (treasured photos, say) in case of fire or theft, for example. You might find a copy on CD or DVD kept at a friend’s place would be just as good, though.
Network
If you have a home network, you could consider a network hard disk which you can connect to your network so everyone can save their files onto it.
The speed of a drive on your network will be directly affected by the slowest part of you network – eg your wifi connection or your router. For this reason, the speed of these drives is less of an issue and ease of set up and use should be a more important consideration.
Connections
USB
External hard drives connect to your computer via a cable. The most common type is USB 2.0 which will be compatible with most modern computers.
FireWire, Ethernet and eSata
However, you’ll also find drives with FireWire connections (found on Macs as well as many PCs these days), Ethernet connections (for use with networks) and eSata connections.
Drive formats
You may come across the terms FAT32 and NTFS when you're choosing hard drives. These acronyms describe the way the data is stored inside the disk.
The maximum single file size you can save to a drive with FAT32 format is 4GB. This should be more than adequate for most people, but if you want to store some truly huge files, it's worth either buying an NTFS drive or converting the drive from FAT32 to NTFS (see your drive’s manual for detail).
Apple Macs can't save to NTFS format so Mac users should use either FAT32 or an alternative format known as HFS (again, consult the drive’s manual for more on this format).