rel="canonical" href="https://www.selfstudyworld.com/" /> Hard Disk Definition, Function, Work Skip to main content

Hard Disk Definition, Function, Work

Hard Disk Definition, Function, Work

The 1950s saw the development of hard drives. They first appeared as huge discs with a 20-inch circumference that could only store a few megabytes. Initially known as "fixed discs" or "Winchesters" (a code name used for a popular IBM product). To distinguish them from "floppy discs," they later adopted the name "hard discs." Instead of the flexible plastic film seen in tapes and floppies, the magnetic media is stored on a hard platter in hard discs.

Hard Disk Definition, Function, Work


Definition of Hard disk

A fixed disc or hard drive are other names for a hard disc. It is said to be a data-storing rigid magnetic disc. It can be found inside a drive unit. A hard disc is a non-volatile storage device that has magnetic discs and platters that spin quickly. Non-volatile data is data that survives the shutdown of the computer.

Internally, our computer systems have it installed. The hard disc, which is made up of one or more platters packed in an airtight shell, is housed inside a drive unit on the motherboard of the computer.
A read/write actuator arm, head actuator, read/write head, spindle, and platter are some of its essential parts.

The function of a Hard disk

A secondary storage system with the capability of long-term data storage is the hard disc. Compared to primary storage devices, secondary storage devices have a lot of storage space. When our computer system shuts down, the data on a hard disc is kept. The operating system, installed programs, papers, and other computer files are just a few examples of the various types of data that can be stored on a hard drive.

IBM first introduced the hard disc in 1956. The first personal computer had a hard drive that was less than 1 megabyte in size, but today's PCs have hard drives that are 1 terabyte in size.

At least one hard drive is built into every computer to store data and programs. The hard drive is referred to as the C drive in the Windows operating system and as the hard drive in the MAC operating system. External hard drives for desktop computers are utilized as backup storage or as extra capacity.

Hard drive capacity is expressed in gigabytes and terabytes. 500GB hard discs are typically standard in contemporary computers. For example, a song that lasts four minutes is approximately 4MB in size, and since there are 1,000 megabytes in a gigabit, a 500GB hard drive can hold approximately 250,000 songs.

Capacity and Performance

Typically, a desktop computer's hard disc has a capacity of between 10 and 40 gigabytes. On the disc, files are used to store data. Simply said, a file is a group of bytes with a name. The bytes could be the ASCII codes for the characters in a text file, or they could be the records in a database, or they could be the pixel colors for a GIF image, or they could be the instructions for a computer program to run. But a file is just a string of bytes, whatever it contains. When a computer software requests a file, the hard drive locates it and transfers each byte to the CPU one at a time.

There are two techniques to evaluate a hard disk's performance:
Data rate - The amount of bytes per second that the disc can send to the CPU is referred to as the data rate. Common rates range from 5 to 40 megabytes per second.

Seek time - The seek time is the interval of time between the CPU making a file request and the CPU receiving the first byte of the requested file. Common intervals range from 10 to 20 milliseconds.

The drive's capacity, or how many bytes it can store, is the other crucial factor.

Advantages of the hard disk

The following is a list of a hard disc drive's benefits:
  • The low price of a hard disc drive is among its many noteworthy benefits.
  • A Hard Disk also has the benefit of being widely accessible in the market.
  • Optical discs are slower than hard discs.
  • HDDs have a great amount of storage space.

Disadvantages of the hard disk

  • The reading and writing speeds of HDDs are slower than those of RAM.
  • HDDs produce noise.
  • Energy inefficiency is another drawback of HDD.
  • HDDs need more electricity.
  • HDDs weigh more than SSDs in terms of form factor.

Popular posts from this blog

Limitations of Terzaghi Theory

Limitations of Terzaghi Theory The value of the coefficient of consolidation has been assumed to be constant.  The distance d of the drainage path cannot be measured accurately in the field. The thickness of the deposit is generally variable, and an average value has to be estimated.  There is sometimes difficulty 1n locating the drainage face, sometimes thin previous seams that can act as good drainage face are missed in the boring operations. The equation is based on the assumption that the consolidation is one-dimensional. In the field, the consolidation is generally 3-dimensional. The lateral drainage may have a significant effect on the time rate of consolidation. The initial consolidation and secondary consolidation have been neglected. Sometimes these form an important part of the total consolidation. In actual practice, the pressure distribution may be far from linear or uniform. Read More Muller-Breslau principle

Price Guard Wire Method

Price Guard Wire Method Some form of  Price Guard Wire Method  is generally used to eliminate the errors caused by leakage currents over insulation. Fig. 3.14 illustrates the operation of This Method. In fig 3.14(a), a high resistance mounted on a piece of insulating material is measured by the ammeter voltmeter method. The micro-ammeter measures the sum of the current through the resistor (IR) and the current through the leakage path around the resistor. The measured value of resistance computed from the readings indicated on the voltmeter and the microammeter, will not be a true value but will be in error.   Figure 3.14 Application of  guard  circuit for measurement of high resistance In fig, 3.14 (b), the  guard  terminal has been added to the resistance terminal block. The  guard  terminal surrounds the resistance terminal entirely and is connected to the battery side of the micro-ammeter. The leakage current IL now

Streamer Theory of Breakdown in Gases

Streamer Theory of Breakdown in Gases According to the Townsend theory firstly, current growth occurs as a result of the ionization process only. But in practice, breakdown voltages were found to depend on the gas pressure and the geometry of the gap. Second chances time lags of the order of 10-5 s, but practically it was observed to occur at a very short time of 10-8 s. Also, the Townsend mechanism predicts a very diffused form of discharge, that actually discharges were found to be filamentary and irregular. Townsend's mechanism failed to explain all these observed phenomena and as a result, The Streamer theory was proposed. The theory predicts the development of a spark discharge directly from a single avalanche in which the space charge developed by the avalanche itself is said to transform the avalanche into a plasma steamer. In Fig 1.7, a single electron starting at the cathode by ionization builds up an avalanche that crosses the gap. The electrons in the a