Virtual Memory

The most significant constituent of the computer is its processor. It is considered to be the heart of the computer. It does all the calculating and processing functions. But it is the computer memory that helps the computer preserve essential information on a computer. Without the existence of a computer memory, the processor will not be able to store all its calculations and processes.

Memory Bank

There are diverse kinds of computer memory meant to store different types of data. The most common computer memory is the Random Access Memory or RAM, which helps you in accessing any stored data if you are aware of the exact location. The exact opposite is Serial Access Memory or SAM, which stores data in a sequence of memory cells that can only be accessed in an array. Another kind of memory is Read Only Memory or ROM. It is a track that is already programmed with exact data that cannot be adapted or changed, hence the name derived as “Read Only”.

Yet another kind of memory is the Virtual Memory. It is an alternate collection of memory addresses. Programs employ these virtual addresses instead of the real addresses to store commands and data. When the program is in reality implemented, the virtual addresses are transformed into genuine memory addresses.

Virtual Memory is a familiar constituent in nearly all operating systems and desktops. It frees up the RAM from idle applications to create space for loading existing applications. A virtual memory works by scrutinizing the data stored in RAM. It removes the data, which is not utilized regularly from RAM to the hard disk, and in turn frees up the space in RAM for loading other important programs. A Virtual Memory makes the computer believe that it has unlimited RAM.

The function of virtual memory is to expand the collection of addresses a program can make use of. For example, virtual memory might include two times more addresses than the main memory. A program utilizing all of virtual memory, thus, would not be capable of fitting in the main memory all at one go. Nonetheless, the computer can implement such a program by replication those segments of the program into main memory that are required at any known point during implementation.

To make the copying of virtual memory into real memory easy, the operating system splits the virtual memory into pages, each of which includes a permanent number of addresses. Each page is accumulated on a disk until it is looked for. When the page is required, the operating system replicates it from the disk to the main memory, decoding the virtual addresses into real addresses. The procedure of interpreting virtual addresses into real addresses is known as mapping.

The Various Advantages And Disadvantages Of Virtual Memory

The main advantage of a Virtual Memory is its capability to load and implement a procedure that needs a bigger amount of memory than what is available for loading the procedure in fragments and then implementing them.  The disadvantage of a Virtual Memory system is that it is usually very slow and needs extra support from the computer’s hardware for address conversions.

The execution speed of a process utilizing Virtual Memory can be equal, but can never go beyond the implementation speed of the same procedure without using Virtual Memory. Thus, we do not get any benefit with regard to the execution speed of the process.  The benefit lies in the capability of the system to get rid of external disintegration.  The other drawback of having Virtual Memory is the likelihood of Thrashing due to extreme Paging and Page faults.