Essentials of Computer Organization and Architecture, 5th Edition

6.5   VIRTUAL MEMORY

You now know that caching allows a computer to access frequently used data from a smaller but faster cache memory. Cache is found near the top of our memory hierarchy. Another important concept inherent in the hierarchy is virtual memory. The purpose of virtual memory is to use the hard disk as an extension of RAM, thus increasing the available address space a process can use. Most personal computers have a relatively small amount (typically around 4GB) of main memory. This is usually not enough memory to hold multiple applications concurrently, such as a word processing application, an email program, and a graphics program, in addition to the operating system itself. Using virtual memory, your computer addresses more ...