My External Hard Disk Not Reading?

What is Delay in Hard Disk Drive reading?

• why is there a delay? Someone gave me these points. Please correct it if there is any mistakes. 1) The CPU initiates the process by commanding the disk drive to read data from a specific sector 2) The head actuator moves the heads accross the disk to the position of the required track. This involves a delay which is refered to as SEEK TIME 3) The sdisk drive waits for a specific sector to spin under the head. Thsi is called the ROTATIONAL DELAY. The average rotation delay is equal to the time required by the hard disk to make half a revolution. Current disks rotate at about 7200-1000 revolutions per minute. 4) The data is read through the heads and transferred to the memory of the computer. This last part also requires time, in this case the DATA TRANSFER DELAY. Please advise on the information above. Is it entirely correct? Thanks again!

• Answer:

  The information is correct although it is missing a few steps. First the CPU has to read the Master file table (MFT) to know where to locate the data in question. The MFT contains the locations of all files on the hard disk.