|
 In the olden days when hard drives were counted in megabytes and the floppy disk was king, backing up a hard drive and transferring files between desktop computers bordered on insanity. Those days of ancient computer history are long gone. These days, when we want to back up a computer, maybe archive some important files, or simply want to transfer data from one computer to another, we have the external hard drive.
Since an external hard drive lives outside the computer, it is ideal for backing up and making more room on your hard drive especially when personal files such as photos, documents, music, and videos can take up a massive amount of space in only a few years. Another advantage of an external drive is that it can even be taken off site for safe keeping.
 The Basics
An external drive, when it comes down to it, is simply a hard drive (yes, the same kind that is in your computer) packed inside an external case. The basic types are: mobile, desktop and network. Mobile drives are small (they usually contain a hard drive that is found in a laptop), sleek and can usually run just off the computer's power, however they also tend to cost more and have smaller capacities than desktop drives.
 Desktop drives usually contain a hard drive the same as those found in a desktop computer. Because of this, these drives will deliver a lot of bang for the buck. Though larger than mobile drives, they cost less per gigabyte and have a much larger capacity propecia 5mg online (even into the terabyte range when multiple drives are placed inside an external case). However, because of their larger physical size and their need for a wall socket to draw power, they tend to be placed somewhere on a computer desk – and stay there.
 Another type of drive is the NAS, or Networked Attached Storage external drive. Because of their specialization and usually very large size, they tend to have a higher cost than either a typical mobile or desktop drive. These will usually be near a router or similar network component and also will be more difficult to set up.
Just as the drive types can vary, the actual design of the external drive can vary. Some may be fortified to withstand travel; some may be designed by famous design groups such as the Lacie line of drives designed by Porsche; and some may have extra features  such as a one-touch backup button or a variety of video and audio ports that let the hard drive be used as a media center.
External drives are typically prebuilt with the drive already in the case and formatted for ease of use. Some users can also make their own external drives by purchasing an empty external drive case and hard drive separately and “building it themselves.” Purchasing an external drive case may be an excellent idea if you already have an extra hard drive laying around.
Drive Interfaces
 Another aspect of an external hard drive that can vary is the interface. By far, the most popular interface is USB 2.0. USB ports are found on just about every computer made. USB 2.0 is rated at 480 mbps (megabits per second), but because of its design, actual transfer speeds are lower than the theoretical speeds. However, USB 2.0 is still plenty fast enough for many users who are simply using the drive for external storage and backup.
 FireWire is another interface and actually comes in two varieties: the original FireWire (also called iLink or IEEE-1394A) and its successor, FireWire 800 (also called IEEE-1394B). The original FireWire is rated at 400 Mbps and FireWire 800 is rated at 800 Mbps. Again, these are theoretical speeds, however because FireWire is designed differently than USB, both will deliver, on average, better throughput than USB 2.0 (especially FireWire800). FireWire is an ideal solution for those looking for faster performance from an external drive.
A relative newcomer is eSATA (external SATA) with a theoretical rating of 3000 Mbps. Its design is such that, even in the real world, it will deliver constantly better performance than either FireWire or  USB. eSATA is not widely implemented, and add-on cards will typically need to be used.
An RJ45 Ethernet interface is used on drives that are designed to be attached to a network and be used as a shared drive. Low cost NAS units can be found for home networks and Gigabit units are designed to run up to 1000 Mbps (but are backwards compatible with slower networks).
With so many interfaces to choose from, many drive makers actually make multiple interface drives that will have two or more of the interfaces on them (though at a nominally higher cost then single interface drives).
Whether for backup or file transfer, adding an external hard drive to your computer is an idea that just makes sense!
|
