Anatomy of a Hard Disk
Hard disk structure and basic features ..
The hardware component with magnetic platters used to store data (information) is called a hard disk.
The magnetic field is covered with a special layer, and the material that performs operations such as reading, writing, and deleting data from this layer is the read/write head placed above and below the platter. The magnetization method is used to record data on the platter. In this method, data is placed in circles called tracks with 0 and 1 symbols to achieve meaningful information storage.
A hard disk consists of the following parts:
Case: It is where all parts are placed and serves to protect these parts from factors such as air, dust, and moisture. Shaft: It is the part in the center that allows the platters to rotate comfortably and quickly. Read/Write Head: It performs the operation of reading and writing data from the platters by creating a magnetic environment. Head Actuator: It helps process information by enabling the read/write head to move on the platter. Connector: It is the part where cables such as IDE and SATA are connected for data transfer between the motherboard and the hard disk. Jumper Pins: They determine which hard disk will have priority when the computer starts, that is, if 2 or more hard disks are connected to the computer, they are used to set which one will have priority for system startup. Jumper: It is used in priority determination by acting as a bridge to jumper pins. Power Input: It is the part where the electrical energy required for the hard disk to work is connected. Seal Strip: It is a special material that protects the internal parts from environments such as air, moisture, heat, and dust, that is, makes the inside of the hard disk airtight. Data Cable: It is used to carry the information read from the platters to the CPU (Central Processing Unit). Disk Platters: These platters determine the size of the hard disk, that is, they can be called the area where information is processed. Case Connection Points: The place where the screw mounting sections are located to place the disk in the case. Circuit Board: It performs the function of electronic information flow. We can say that a control board "controls" the disk. The physical locations of sectors, tracks, bad sectors, and the area called landing zone on the platters are recorded on the control board, and the control board directs the heads to these areas. Hard disks communicate with our computers using data buses, and establishing the connection between the data bus and the hard disk is one of the most important tasks of the control board.
Features that Determine the Capacity and Performance of a Hard Disk
In hard disks, capacity is determined by the data density on the platters and the number of platters. The most important concepts we use when commenting on the performance of a hard disk are the rotation speed of the platters, access time, and data transfer rate. Rotation Speed: It is the rotation speed of the platter. While platters in IDE disks we use in our desktop systems generally rotate at 5400 or 7200 RPM (Rotates Per Minute, rotation speed per minute), this speed can reach up to 15000 RPM in SCSI disks. Access Time: The time it takes for the read/write head to reach a point (sector) on the disk. While the average access time is below 10 ms in modern IDE disks, it is even lower in SCSI disks. Data Transfer Rate: It is the amount of data that the hard disk can transfer per second. It varies according to the interface used and the characteristics of the disk.