Skip to main content

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

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.





Labels:

Comments

Post a Comment

Popular posts from this blog

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...
Post a Comment
Read more

Bus Topology Advantages Disadvantages

Bus Topology Bus topology is the simplest network topology . In bus topology , all computers in network are connected to a common communication wire. This wire is called BUS. Terminators are used at both ends of wire. Bus Topology is Cheap, easy to handle and implement. Bus Topology require less cable. Bus Topology is best suited for small networks. Working of Bus Topology with Advantages and Disadvantages Advantages of Bus Network Topology 1. It is very simple topology . 2. It is easy to use. 3. It needs small amount of wire for connecting computers. 4. It is less expensive due to small wire needed. 5. If one computer fails, it does not disturb the other computers in network. Other computers will continue to share information and other resources with other connected computers. Disadvantages of Bus Network Topology 1. Only small number of computers can be connected in a bus network . 2. Network speed slows down as the number of computer increases in b...
Post a Comment
Read more

Important Objective Type Questions 101-155

MMC stands for multimedia card. SD stands for secure digital card. System Bus  is used to connect main components of a computer such as cpu and main memory. A Port is an interface or a point of attachments. POS stands for Point Of Sale terminal. ATM stands for Automated Teller Machine. PIN stands for Personal identification number. Kbps stands for kilobits per second. Mbps stands for megabits per second. A port that transmits one bit at a time is called Serial Port. A type of port that transmits many bits at a time is called Parallel Port. LPT stands for Line Printer. Examples of system software are Operating System, Utility Programs and Device Drivers. Examples of operating systems are DOS, Windows, Unix and Linux. Examples of Utility programs are File Manager, Image Viewer, Disk Scanner and File Compressor. Software used to detect and remove viruses is called Antivirus . Examples of antivirus programs are Mcaffee, Avast, ...
3 comments
Read more