The definition of a hard disk
A hard disk is a device for mass storage. You no longer need your own computer to consult stored data. Thanks to the hard disk, data can also be consulted through another computer. This disk enables to add or remove information (rewritable) unlike the classic storage media such as writable CD’s or DVDs’ (non rewritable). Choosing a suitable hard disk depends on the goals you wish to obtain.
An external hard disk has different functions:
Saving important data. Transferring a large amount of data to another computer. Visualizing multimedia on your television.
How to choose your external hard disk
- Large storage capacity (500 GB up to 3 Tb)
- Easy to use (with or without external) charger
- Continuous consultation of data everywhere (on condition that there is a computer)
Things to take into account:
- There are two sizes available in external hard disks: the 2.5” (lighter then the 3.5” and especially used as a transport means for data consulting in other locations) and the 3.5” (used as a data back-up system). A 3.5” hard disk does not have an external supply cable and can be used immediately after connection with an USB cable. Hard disks of 3.5” are often provided with an external charger that needs to be connected with the net in order to use the stored data.
- The difference in storage capacity (there are large and small hard disks, as stated above)
- The difference in the number of rotations/minute (RPM or rounds/minute). The basic rotations for an external hard disk are 4200, 5400 and 7200 RPM our rounds/minute. The higher the speed the faster a computer can recognize the data on the hard disk.
- If you wish to initiate a specific research or writing process, the access time is important. A convenient access time is 12 ms (milliseconds). The best hard disks do not cross 9 ms.
- Different interfaces for hard disks: USB: most frequently used (after connection with USB cable you can access the stored data) WIFI: wireless system which can be used to share data with other computers on the same connected network Firewire: comparable with USB, but a product developed by Apple. The maximum speed for data transferring with USB is 400 Mb/sec.. With Firewire this can reach 800 Mb/sec. The cache memory stores frequently used data for quick and easy access. This memory can go from 8 up to 12 Mb.
The information above should help you in making the best decision for buying a suitable hard disk.