An external hard drive serves many purposes, therefore it is very important to carefully consider all the options before buying an external hard drive. The main purpose of an external hard drive is to work as a backup device. You can easily sync an external hard drive with the internal drive of your computer and thus can safeguard your data. So following are the main points you need to keep in mind while shopping for an external hard drive:
Hard Disk Capacity: This is one of the most important criterions that will determine the number of options available for you. Although, the external drives are available in a wide range of storage capacity but you have to keep one thing in mind that bigger the capacity is, the more the money you need to shell out for the drive. So, the best thing to do is to carry a tradeoff between your storage requirement and your monetary budget.
Data Transfer Speed: This criterion is very important as it determines the time taken for the transfer of data. Typically, a 3.5 inch internal SATA hard drive gives you 7200rpm. So, while buying an external hard drive, you might want to go with a drive which gives you 7200rpm minimum. You can also opt for higher rotation of 10000rpm or more, depending on your requirements. Various key words you need to remember are RPM, Seek time and buffer size. The seek time for an external hard drive should be 10 milliseconds or less, whereas the buffer size should be 4MB or more.
Connectivity: Internal hard drives are mounted on the motherboard inside your computer but this is not the case with your external hard drive. The major connectivity options are USB or Firewire. So, you need to consider that the connectivity option provided by your computer is compatible with the external hard drive. Firewire is a preferable and faster option but many computers do not offer this type of connectivity. Even if both your computer and Firewire are USB compatible even then you need to be careful about the type of USB port. Therefore, find out whether your computer has USB1.0 or US2.0.
Size and Other Physical Factors: Not all external hard drives are portable. Nowadays, external hard drives are available in a variety of colors, shapes and sizes. You should carefully evaluate your requirements before buying one. If you need to carry your drive with you then you might want one which is lighter in weight and is smaller in size. External hard drive tend to make noise while operating, so if you work in an enclosed environment, take into consideration the noise factor as well.
Another important point is to for the highest capacity drive that you can afford to buy. High-end external hard drives with additional features such as one-touch back up facility. But the above list compiles the universal factors which will help you in making intelligent decision about an external hard drive.