Virtual memory is a computer science term for an advanced form of memory that is used by most operating systems today. Instead of assigning to a program an exclusive part of the working memory that is available, each program can get a virtual equivalent of a full-fledged computer. The operating system is then hidden under this virtual memory space and handles all the real memory resources so that all running programs get what they need, but not more. This allows avoid wastage and memory can be exploited.
Memory that is not used at any given time can be stored on another medium, usually secondary storage such as hard drives, until needed. Due to the fact that a hard drive usually has much greater storage capacity than the main memory of a computer, all programs can have a lot more virtual memory than the RAM available in your computer.
For example, a program does not need memory C to work from A to B. C can then be stored until the work of C begins. Once the work from B to C started and A is no longer needed it then can be stored.
A program that is sleeping or waiting for data from the keyboard or the network does not need any resources until the data comes, the operating system can then store the whole program and then bring it to life again when the data arrived.
In severe cases, this can cause a phenomenon called thrashing when multiple programs at the same time want to have access to more data than it is really can manage. The data must then be constantly moved to and from the hard drive so that it can be processed in working memory just when they are needed. Since today’s primary flash drives are much faster than hard disks, whose thrashing is perceived as a very painful loss of performance. This phenomenon occurs easily on older computers without enough RAM or when too many programs are running simultaneously.
Since a hard drive is a relatively slow medium, paging to disk works never as good as really needed. However, hard drives are mighty cheap in comparison with working memory and a computer may well adapt the use of the hard drive for storing data for the user to label as little as possible in the process.
Virtual memory is different and also protects applications from each other. Only the operating system knows about all the different programs that are running, the individual program held under the illusion that it is working completely alone on the computer. Memory protection is not something the user noticing, all he sees is a well-functioning program.
Use free sample research paper on virtual memory to write a successful research proposal on the topic.
At EssayLib.com writing service you can order a custom research paper on Virtual Memory topics. Your research paper will be written from scratch. We hire top-rated Ph.D. and Master’s writers only to provide students with professional research paper assistance at affordable rates. Each customer will get a non-plagiarized paper with timely delivery. Just visit our website and fill in the order form with all research paper details:
Enjoy our professional research paper writing service!