Hard Drive Speed

O The hard disks inside a magnetic hard drive typically spin continually at a rate of between 7,200 and 15,000 revolutions per minute. O The total time that it takes for a hard drive to read or write data is called the disk access time and requires the following three steps: 1. Move the read/write heads to the cylinder that contains (or will contain) the desired data—called seek time. 2. Rotate the hard disks into the proper position so that the read/write heads are located over the part of the cylinder to be used—called rotational delay. 3. Move the data to memory, or transferring the data from memory—called data movement time.