Background

• The Universal Serial Bus (USB) is a method of connecting external devices to computers, servers and laptops. Widely used to store backups or additional data files, external USB hard drives connect via a USB port.
  
  

History

• The history of USB technology plays a key role in determining the performance of an external USB drive. USB 1.1, the first commonly used USB standard, had a maximum data transfer speed of 12 megabytes per second (Mbps). USB 2.0, available since 2002, increases this speed by 40 times, to 480 Mbps.
  
  

Considerations

• Due to the advances in USB technology, the type of USB port through which the external drive connects can have a significant impact on performance. A modern USB 2.0 drive will, regardless of specification, only be able to transfer data at slower speeds if connected to a USB 1.1 port on an older computer.
  
  

Specifications

• The specifications of the drive itself will also determine its performance. The rotation speed, measured in RPM, will have an impact on how quickly the drive can read and write data.
  
  

Warning

• The number of tasks you perform at any given time will affect the performance of your external hard drive. Copying files to or from the external drive while the computer is busy performing other tasks will diminish performance.