This refers to the excessive use of virtual memory paging to compensate for having insufficient real physical memory to hold all of the applications and data that are in use. Especially if you are using many applications or large files, and also if there isn't a great deal of real memory in the PC, the operating system will have to move some of the contents of memory to the hard disk when it runs out of space. Then, when you need whatever was swapped to disk, it is loaded and something else is swapped to the disk. Read this section on virtual memory and this section on choosing a sensible memory size for the operating system and application you are using. If you can afford to do so, upgrade the amount of physical memory in the system, especially if you don't have enough memory in the PC for optimal performance based on your operating system.
Memory is cheap today and it provides great performance improvement in many cases.
Consult this section of the Optimization Guide for suggestions on optimizing the virtual memory setup of your system. These simple steps can greatly improve performance at no cost. Reduce the number of applications running in the system, and reduce the number of data files you have open. If you are finished using something, close it to free up memory for programs you are still using. This page has been served 7874 times.