the _________ is the primary storage device of a personal computer.
Hard Disk. â¢ The hard disk drive is the main, and usually largest, data storage device in a computer. â¢ It can store anywhere from 160 gigabytes to 2. terabytes. â¢ Hard disk speed is the speed at which content can. be read and written on a hard disk. â¢ A hard disk unit comes with a set rotation speed.