Memory and Virtual Memory Management

What is Memory Management?

One of the main functions of Operating systems is Memory Management. Memory Management may be defined as the process of managing the optimal use of main memory that is RAM (Random Access Memory). RAM is much faster than hard disk. So RAM is used to store data and instructions temporarily while they are being executed by CPU ( Central Processing Unit or PROCESSOR ). CPU can get data and instructions from RAM much faster that from hard disk.

As we know CPU is a very very fast device. It may execute billions of instructions per second. CPU will have to wait for data and instruction from hard disk because getting data from hard disk is very slow. That is why RAM is used. So data and instructions needed for execution are brought into main memory that is RAM first. Now RAM provides data and instructions to CPU rapidly.

What is Memory Management and virtual memory management

Operating System allocates the required memory are in main memory to programs that are a candidate for execution. The allocated memory area will be de-allocated when the program will finish execution.

What is Virtual Memory?

Some times, main memory that is RAM is not enough to run larger programs. In this case, some operating systems apply the technique of VIRTUAL MEMORY to overcome the problem of small RAM.

The operating system uses a particular area of hard disk as additional RAM (virtually). The most wanted part of the program in execution may be kept in RAM while the remaining part of that program may on the particular part of the hard disk. This is called Virtual Memory. The area of hard disk used for virtual memory is called a SWAP file. The Swap file is used to exchange data and instructions of a running program between RAM and Hard disk.

Comments

Explain Different Types Of Data

DATA Data is the collection of raw facts and figures. It is without any proper meaning. Data may be collection of words, numbers, graphics or sounds. What is data? Explain different types of data Examples of Data 1) Student Data on Admission Forms When students get admission in a college. They fill admission form. This form contains raw facts (data of student) like name, father’s name, address of student etc. 2) Data of Citizens During census, data of all citizens is collected. 3) Survey Data Different companies collect data by survey to know the opinion of people about their product. 4) Students Examination data In examination data about obtained marks of different subjects for all students is collected. Different Types Of Data There are following main types of Data. 1) NUMERIC DATA Numeric data consists of 0 to 9 digits, + and – sign and dec...

What are Dual Devices or Both Input/ Output Devices

The devices that can be used to perform both functions -input and output- are called Dual Devices. These devices are also called Dual Purpose Devices or Both Input/Output Devices. With the help of a dual purpose device, we can enter data into computer as well as we can output data from the computer to outside world. For example, Dual devices include: Touch Screen Monitor, Modem, Network Interface Card, Sound card, Hard disk drive, Floppy disk Drive, Magnetic Tape Drive CD-Writer and DVD-Writer etc. These are also called Input/output devices, because they perform both functions. Touch Screen Monitor Dual Devices or Both Input / Output Devices - Touch screens Touch Screen Monitor is an input/output device. It uses a special touch sensitive screen. The User can enter data by touching icons or menus on the screen. As soon as the user selects a command from menu, output is displayed on screen. Commonly touch screen monitors use sensors to detect touch of finger. ...

Advantages and Disadvantages of Tree Topology

Tree Topology Actually, a Tree topology is the combination of two topologies: bus topology and star topology . A tree topology combines the characteristics of bus and star topologies. It consists of groups of computer connected as star topology. These groups are then connected to a central communication medium (bus cable). Advantages and Disadvantages of Tree Network Topology Advantages of Tree Network Topology 1. Many software and hardware vendors support tree topology . 2. It provides point-to-point wiring for individual groups. Disadvantages of Tree Network Topology 1. If the main backbone line breaks, the entire tree network goes down . 2. A tree network is more difficult to configure and maintain. 3. If any hub fails, related segment will be removed from the network. Read More on Networking and Networks 1 Explain Advantages Of Networks 2 Types Of Computer Networks...

Perfect Computer Notes

Search This Blog