What is Virtual Memory Size?

Virtual memory size is an abstract design. Virtual memory is a technique that permits the system to think there's much more storage space than there actually is by keeping latent aspects of running applications on the hard disk and allowing multiple programs to run at the same time. Virtual memory is a method used by the operating system to optimize and increase the storage capacity and power of its functioning memory, without the need of installing additional hardware.

In hardware terms, PCs come with a specific amount of Random Access Memory (RAM) often 128 or 64 MB. The capacity of RAM determines the PC's memory capacity and the number of applications it can run at a time. But in an effort to increase the performance, operating systems are designed to trick themselves and recognize more available RAM than there really is. This can be done by moving unused parts of running application from the RAM to the hard disk, cleaning up RAM capacity and enabling more applications to run at once. The moving process of unused application parts from RAM to the hard disk is called "swapping."

A 64 MB computer will need at least two times the amount of RAM to support the OS, but can run the system and some other programs with the use of virtual memory. The virtual memory is saved in a "paging file" on the hard disk. When the OS identifies application files that have not been used lately, it changes them from the RAM to virtual memory paging file. The size of the virtual memory is the data amount that can be saved on the paging file.

If you have received a Windows error telling you that your system has low virtual memory, you may want to enlarge your paging file in order to increase the amount of application data that can be saved there. But too much upgrading your virtual memory paging file will also cause too much swapping (a process called "thrashing") that will impair total performance.

If you are running Windows XP, follow these simple steps in order to upgrade your paging file size:

If you're running Windows Vista:

Enter new initial and the maximum size value amounts. It is a good idea to set the numbers similar so your PC does not have to switch back and forth.

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