Virtual Memory and Computer Speed

Virtual memory has been used in modern operating systems such as Microsoft Windows for decades but it is still not widely understood. The disk cache for virtual memory on Windows is called the paging file or pagefile.sys and on Unix operating systems it uses it's own partition. If you use a Macintosh and you have version X or higher, your system uses the same scheme as Unix.

Some applications need access to a large amount of memory (also called RAM) to function correctly. If you run one or more of these kinds of applications, your system may run out of physical memory (or RAM) for the applications to use. This is where virtual memory comes into play. The operating system tells the application that there is more RAM available than physical RAM on the system and when the application attempts to use this memory, the operating system uses the hard disk instead of physical RAM to store the data. As most computer users know, one way to quickly get a speed boost for you system is to buy more RAM so that virtual memory is not used as much.

If you have a new PC, chances are you may not need to tweak virtual memory to get more performance. It is important to remember that in 99% of cases, you should not turn off virtual memory on your system. To manage virtual memory, right click on "My Computer", choose "Properties", then click the "Advanced" tab and click the settings button. Now click the change button under virtual memory to bring up the virtual memory options page. Now select your primary drive, normally this is your C:\ drive. For a quick rule of thumb, set your paging file size to double the amount of RAM you have. For example, if you have 1 gigabyte of RAM, set the paging file size to 2 gigabytes. If you have a less used drive on your system, consider moving the paging file to this drive to allow your primary drive to be used for other, more important applications.

If you really need maximum PC speed and you have more than 2 gigabytes of RAM on your system, consider turning off the paging file altogether. Also this can lead to potential problems when trying to run large applications, in your day-to-day use, you should notice a definite improvement because Windows will no longer attempt to give applications too much memory and start thrashing the hard drive.