What is virtual memory, and why is it important?
Virtual memory is basically space on your hard drive that is allocated by your operating system to be used as a supplemental reserve of memory when your an application’s RAM limit has been maxed out by that application.
For instance, if you compare two 50 MB files in UltraCompare, obviously this is a very memory-intensive process. Like most PC users, you’re ALSO concurrently running UltraEdit, a web browser, an email client, anti-virus, and other utilities…and the memory-intensive large file compare coupled with the RAM usage by these other utilities may exceed your system’s available RAM.
In this case, Windows will typically move some of the information stored in RAM over to your hard disk, where there is plenty of free space.
Once a certain internal threshold is reached, your operating system may direct any further memory usage of UltraCompare over to virtual memory so other applications running on your system are not affected by the large amount of memory required for the compare.
