External hard drives provide a solution to both storage and backup problems. Unlike trying to install an additional internal hard drive in your computer, most external devices are plug-and-play simple to hook up, and the number of external drives that you use is limited only by your budget. Fortunately, the price of external hard drives keeps dropping even as capacities increase, so the cost per gigabyte can be quite reasonable.
The first decision you’ll have to make is how much additional storage you need or want. External hard drives are currently available in capacities from about 80 GB to 1 terabyte or higher (you may find a single unit that contains two 1 terabyte disks). The most common sizes for external hard drives generally range from about 150 GB to 500 GB, so there are enough choices to fit different requirements and budgets.
If you’re a prolific shooter and/or capture video as well as still /images, you obviously need more storage space than if you only shot still /images from time to time. Those of you who are mathematically inclined can run some numbers to estimate how many megabytes of /images you’ll need to store and figure your capacity requirements from there.
In addition to your photographic habits, it’s important to decide whether or not you want to use one or more external hard drives to back up data. If so, how much data will you be backing up? Everything on your computer’s hard drive? Another external hard drive? The answers to these questions should also help guide you to a capacity that will meet your needs.
The type of connection used for hooking up an external hard drive to your computer will help determine how fast (or slow) the computer will be able to read and write data. Since external hard drives come with different options, take an inventory of available computer ports before you make a decision about which drive to purchase.