Hard Drive Enclosures - The Basics

Hard Drive Enclosures (also known as Caddy's) are rigid cases that Hard Disk Drives "sit" inside. They are designed to support standard Hard Disk Drives of all types and sizes and once installed inside the enclosure, the enclosure can be connected to the computer via USB, Firewire or e-SATA.

Enclosures are often used to house hard disk drives salvaged from an old PC but they can also be used in conjunction with new disks (You'll need to format the new hard drive once in the enclosure before it shows up on your PC). The benefit of using a new disk is that you will typically buy a hard drive with a larger storage capacity than any hard drive you salvage. Salvaged hard drives are effectively "free" and the motivation for using a salvaged Drive is often to recover data from the drive (particularly if it was removed from a failed PC) and then to put the drive to good use as a back-up by using it in an enclosure.

Because enclosures are external devices they are portable and can be used on multiple PC's or used to transport large amounts of data between say work and home. The smaller enclosures used to house HDD's from Laptop PC's don't even require an external power supply because they draw all of their power from the USB connection. Larger enclosures will have their own independent power supply. Key benefits of Hard Drive Enclosures are:

Flexibility of Connection Type: Enclosures give you the freedom to connect your hard drive to your PC in a variety of ways. USB is the most common but you can now buy enclosures with Firewire or e-SATA connection options. Typically USB is the default connection and Firewire and/or e-SATA available in addition to the default USB connection.. Enclosures with dual connection options like this are referred to as Combo Hard Drive Enclosures.

Interface: Most new hard disks are now SATA (Serial-ATA) disks but if you are looking to use a hard disk salvaged from an old PC it's probably going to have an IDE interface (also described as ATA or PATA). The IDE interface is pretty easy to distinguish as it has 2 rows of 22 Pins along the connection interface. A SATA Hard Disk will have to simple plastic looking connectors. Ensure you buy your hard drive enclosure with the right interface.

Back Up: External hard drives can be used to back-up selected files, folders or for creating a ghost image of the main hard disk installed on a PC. In the event of a failure of the main hard drive the a ghostedback up can then be used to get you up and running again in no time at all. Some enclosures come with "back-up buttons" and software that make this easy. If you buy a hard drive enclosure without this feature and you don't want to manually manage the backing up of files you could consider popular software solutions like Acronis True Image .

If like many the use if the external hard drive is to copy or back-up selected files then its simply a matter of selecting the external drive as the target drive to save to or dragging and dropping files onto the external drive.

Security: If you have sensitive or financial data then it makes sense to store this on the external HDD. Because this drive is independently powered it can be turned off when not in use and this then removes it from the threat of any virus, or Trojan horse software. It also gives you the freedom to physically remove the enclosure and store it securely away from the PC

Archiving: Whether you are downloading music and videos from the Internet, saving Digital photo's from your camera or digitizing your old record collection today are rapidly accumulating very large amounts of data and when all of this data is stored on your primary PC's drive it can cause problems with access speeds, increase the need for defragmentation of the Hard disk etc.  Enclosures allow you to move or duplicate this data onto an external hard drive thus enhancing the performance of your primary drive.

Running an alternative Operating Systems: If you ever fancied having a "play" with Linux but don't want to install it on your PC then you could install it on a hard drive in an enclosure and run it from this. You will need to tweak you Motherboard BIOS settings if you want to boot from the external hard drive as well as the primary drive installed on your PC but it's not that hard