Things to consider when buying an External Hard Drive.

There are many models and brands of external hard drive available on the market today.  When purchasing the right drive for your requirements there are a number of points to consider:

 

1.  Storage Capacity

External hard drives are now available up to 2TB in size.  You will need to consider how much disk space you need for your requirements.  If you are backing up valuable data from your computer then you first need to establish how much disk space you are using on the computer then purchase a disk with sufficient disk space.  Also make sure you account for data expansion.  How much disk space will you need in the foreseeable future ?  Storing photographs and especially HD Video will require larger amounts of data storage than files such as Word documents or Excel spreadsheets, so you will need to calculate what data storage you need for the type of files you are storing. 

2. Connection Type (e.g. USB, Firewire, Wireless)

USB

The most common connection interface for external hard drives is USB (Universal Serial Bus).  Virtually every computer system, mobile phone, or camera (still or video), now have USB connections for easy interactivity with other USB devices, such as external hard drives. 

Firewire

Firewire still provides a very fast data connection between computer systems and hard drives.  Firewire was released in the 1990's by apple, it is very similar to USB and is still used and developed today.  Because of better marketing USB has become more popular in recent times and is therefore now more common than firewire. 

Ethernet

Ethernet is the interface used to connect computer systems to a network.  External hard drives are available that use the Ethernet interface.  These are commonly known as NAS (Network Attached Storage) devices.  NAS devices are purposely designed for the use of file sharing across networks.  They tend not to be so portable, and are also expandable to be able to accommodate several disks for extra data storage and for redundancy (fault tolerance). 

Wireless

Wireless external hard drives are usually Ethernet but can be connected via wireless much the same as you would connect your computer to a router for internet connection.  External Hard drives are also available using bluetooth connections, but are much less common nowadays.

 3. Physical Size (Dimensions)

If you intend travelling with an external hard drive then size may be a consideration.  USB External drives are now typically available about the size of a passport, or even the size of some mobile phones.  These tend to also be light in weight and so therefore with these dimensions are easily portable and can be stored in your computer bag or rucksack.  External drives that require an external power source, however, will be heavier to carry and will take up more storage space.  Such drives are not usually favourable as a portable external hard drive solution.

 4. Powered or non-powered.

Early versions of USB external hard drives required their own power source.  However with the course of technology USB drives have become more compact and power efficient and can now draw the power directly from the computer or laptop they are connected to.  A powered USB drive requires its own power supply in the form of a transformer box to step the voltage down from 110 to 6, 9 or 18volts.  A powered external disk is therefore not as suitable as a portable drive as a non-powered disk, because of additional equipment and weight required to run it.

 5. Portability

 As mentioned above non-powered external hard drives are far more portable because of their weight as they do not require an additional power adapter.  Also very popular are USB flash drives, otherwise known as Pen Drives, or Memory Sticks.  These are the size and shape of a cigarette lighter and are very light and small so will easily fit in a pocket, purse or small computer compartment.  USB Flash drives can now hold up to 128GB of data (as of Q1 2012), so are a great portable and compact data resource for anybody with a PC or MAC on the go.