Differences Between an Internal Hard Drive and an External Hard Drive

Internal Hard Drive vs External Hard Drive

If you are planning to add storage space to your computer, you’ve probably made the decision to  either get an internal hard drive or an external hard drive. The main difference between an internal hard drive and an external hard drive is their purpose. Internal hard drives are meant to be fixed on the computer that they are going to be used on. Of course, you can still move an internal hard drive from one PC to another, but it is more time consuming, and you need to open up the computer. On the other hand, an external hard drive is made with portability in mind. It usually connects via connectors like USB and Firewire, so you can just plug it in right away.

Internal and external hard drives are physically the same, except that external hard drives come with an enclosure that protects the actual drive and provides the necessary interface to the computer’s ports. This minor difference has a number of significant effects. First, external hard drives tend to be more expensive than internal hard drives due to the enclosure.

Additionally, external hard drives are much slower compared to internal hard drives. This is not an issue with the actual drive but with the interface. USB and Firewire are considerably slower than SATA, and the speed of the connection is always dictated by the slowest factor in the chain. A newer interface known as eSATA allows external hard drives to interface at SATA speeds, but the added hassle of a separate power cable caused a very slow acceptance among manufacturers and consumers.

External hard drives use the 2.5 form factor, which is also used by laptops, to minimize its size and improve portability. So if you compare them side by side, external hard drives are smaller compared to the 3.5-inch form factor of desktop hard drives even with the added enclosure.

You should really determine what the use of the hard drive you want will be. If you are just going to use it on one PC, then an internal hard drive is not only better, it is also cheaper. If you like to transfer huge amounts of files between computers, or you want to keep back-ups away from your computer, then an external hard drive is the more convenient option.

Summary:

  1. External hard drives are portable while internal hard drives are not.
  2. External hard drives are more expensive than internal hard drives.
  3. External hard drives are much slower than internal hard drives.
  4. External hard drives are smaller than desktop internal hard drives.