One important decision will focus on how it connects to the computer. USB and FireWire are the most popular options today. This article will focus on USB because it is more widely used and in most cases cheaper than FireWire. The type of USB drives that will be discussed are Flash & Hard-Drives. These will be compared to each other using three criteria:
- Storage Space
- Speed
- Security / Portability
External Drive Size : Storage Space
Many will buy an external drive for doing backups of important documents or the whole computer. It may also act as an auxiliary storage system if space is at a premium on the existing computer or to store audio, video and picture files. Estimate how much space is needed for everything that will be done on the drive then double or triple that figure. Try to plan at least one year into the future when doing this.
If storage requirements are limited (less than 10GB), then a flash drive will be adequate. When more than 50GB is needed, then an external hard-drive normally makes more sense. The cost for each GB of storage is much more expensive when a flash drive is chosen.
Hard Drive and Flash Drive Speed
Some flash drives are capable of 25MB per second data transfer rates. Hard drives can perform much faster, in some cases transferring data at 60MB per second. Another drawback of flash drives is that the data writing rates are sometimes twice as slow as the rate at which information is read. Most data operations will not be a problem at these slower speeds. If large video files and virtualization images will be used however, this might be a concern.
Another consideration will be the speed limitations of USB itself. The fastest USB 2.0 data transmission speed is 480Mb/s (Megabits/second) or about 30MB/s (Megabytes/second). No matter how fast a hard-drive is, it will be limited to this speed when sending data back and forth to the computer.
Security / Portability of External Drives and Flash Drives
If an external drive must be portable, it normally brings up concerns about protecting the data on it which is why these topics are examined together. Many will store documents on a drive that they need to have with them at home or work or school or even on the road when traveling. Because USB drives will connect to most any PC or Mac, portability is practically built-in.
The size of flash drives makes them the clear winner in this area however and they are also powered by the USB port so no power cord is needed. Some USB hard-drives do not need power cords, but they still will not fit on a key chain or in a shirt pocket.
While this portability is convenient, it does raise concerns about losing confidential data if it is stolen. Encrypting the data is one way to make sure that even if it is lost, the information will not be compromised. Some USB flash and hard-drives are sold with encryption capabilities built-in. If the one purchased does not do this, then encryption might be possible through the operating system. Encryption will slow down read and write operations.
The choices available when buying external drives are growing every month. By carefully examining the options available it is possible to come to a decision that will make managing computer data easier.
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