How to access the disk data, Computer Engineering

Assignment Help:

Q. How to Access the Disk Data?

Disks operate is semi-random mode of operation and generally referenced block wise. The data access time on a disk comprises two major components:

  • Seek time: Time to position head on a particular track. On a fixed head disks it's time taken by electronic circuit to select needed head whereas in movable head disks it's time needed to move head to a specific track.
  • Latency time: This is time needed by a sector to reach below read/write head. On an average it's half of time taken for a rotation by disk.

In addition to seek and latency time the time taken to transfer a (read/write) block of words can be considered however normally it is too small in comparison to seek time and latency and in general disk access time is concerned to be sum of seek time and latency time. Because access time of disks is large so it is advisable to read a sizeable part of data in a single go and so disks are referenced block wise. As a matter of fact you will find that in most of computer system input/output involving disk is given a very high priority. Fundamental reason for such priority is latency time which is needed once the block which is to be read passes below read-write head. It may take time of order of milliseconds to do it again, in turn delaying Input /Output and lowering performance of system.


Related Discussions:- How to access the disk data

Show the developments that happened in third generation, Q. Show the develo...

Q. Show the developments that happened in third generation? The main developments that happened in third generation can be summarized as below: Application of IC circuit

Show the memory hierarchy of computer system, Q. Show the Memory Hierarchy ...

Q. Show the Memory Hierarchy of computer system ? Memory in a computer system is essential for storage and subsequent retrieval of instructions and data. A computer system uses

What is ram parity, RAM parity checking is the storing of a redundant parit...

RAM parity checking is the storing of a redundant parity bit showing the parity odd or even of a small amount of computer data typically one byte stored in random access memory, an

Input - output devices using device controller, Q. Input - output Devices u...

Q. Input - output Devices using Device Controller? A device controller needs not to necessarily control a single device. It can typically control multiple I/O devices. It come

What do you mean by inline function, The idea behind inline functions is to...

The idea behind inline functions is to insert the code of a known function at the point where the function is called. If done carefully, this can improve the application's performa

What is input - output commands, Q. What is Input - Output commands? Th...

Q. What is Input - Output commands? There are four kinds of I/O commands which an I/O interface can receive when it's addressed by a processor: Control : This type of c

What is a zombie, What is a zombie? When a program forks and the child ...

What is a zombie? When a program forks and the child finishes before the parent, the kernel still keeps some of its information about the child in case the parent might require

What is strobe, What is Strobe. Asynchronous data are transfer among tw...

What is Strobe. Asynchronous data are transfer among two independent unit needs that control signals to be transmitted among the communicating units to indicate the time at whi

Computer Architecture, As an advocate of CISC architecture to RISC architec...

As an advocate of CISC architecture to RISC architecture, what are the merits and demerits of CISC to RISC architecture

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd