What Are the Components Inside a Hard Drive?

A hard drive is an essential part of your computer. The hard drive is the hardware component that stores your important data. You may not know that inside a hard drive are many parts, some moving, which help speedily record and store your important data. Understanding the parts that make a hard drive work can help you when repairing, replacing or purchasing a hard drive.

Platter

The platter is the flat disk part of the hard drive. The platter is made up of a hard material--usually aluminum, but it varies--which is coated by material with a magnetic charge. According to "The Complete Guide to A+ Certification" by Michael Graves, the magnetic material is the part of the platter which stores the data. The magnetic charges record zeros and 1s which can be interpreted as data by the computer. Each set of magnetic particles is organized in a collection in a unit called a bit. New hard-drive technology uses thin-film metals and glass platters to increase efficiency and drive storage capacity.

Heads

The heads read and write the information to and from the drive platter. Heads are also called read-write heads. The heads write bits of magnetic information onto the platter. The closer the head is to the platter, the more efficiently it is able to read information, but a close-mounted head is more likely to have contact with a platter, potentially damaging the information. Each platter requires one head for each surface of the hard drive that needs to be read simultaneously by the head. So, if you have a two-side platter in your hard drive, you need two heads to read the sides of the platter.

Actuator arms

The actuator arm moves the read-write head to the proper area of the platter. The head of a hard drive is mounted on the actuator arm, which moves it in order to correctly read and write the information. The actuator arm also helps keep the head an optimal distance from the hard drive platter to preserve the drive's speed and efficiency and protect the disk.

Actuator mechanism

The actuator mechanism moves the actuator arm into the right place to read and write data to the hard drive platter. A controller directs the actuator to the track which is slotted for the relevant information. Most hard drive manufacturers use either a motor or a magnetic coil to move the actuator arm into place.

Head Parking

Head parking is a vital part of the construction of a hard drive. Head parking maintains the small space between the head and platter, protecting the platter from suffering damage from the head. According to Graves, the head parking acts as a landing zone for the spinning platter for when the computer is powered off. Head parking can also protect the hard drive when the computer is lightly struck or jarred, but it cannot stop the hard drive from breaking when a severe blow is dealt to the hard drive, like a car accident or an angry kick to the computer.

References

• The Complete Guide to A+ Certfication; Michael Graves; 2006
• Hard Disk Construction