Posted 06 August 2005 - 02:34 PM
Virtual memory is storage space on your hard drive for programs that need more memory than is available from the amount of Ram you have installed on your computer.
From Windows help:
Windows 2000 allocates resources according to its settings and manages devices according to what your system needs. However, you can adjust Windows 2000 to improve its performance, particularly by changing the way Windows 2000 uses processor time and memory.
Managing processor time
System processing is managed directly by Windows 2000, which can allocate tasks between processors while also managing multiple processes on a single processor. However, you can set Windows 2000 to give a greater proportion of processor time to the application in which you are currently working. This can result in faster response time from the programs and applications you use while you work. Or, if you have background processes such as printing or disk backup that you want to run while you work, you may prefer to have Windows 2000 share processor resources equally between background and foreground programs.
Managing Computer Memory
When your computer is running low on RAM and more is needed immediately to complete your current task, Windows 2000 uses hard drive space to simulate system RAM. In Windows 2000, this is known as Virtual Memory, and often called the pagefile. This is similar to the UNIX swapfile. The default size of the virtual memory pagefile (appropriately named pagefile.sys) created during installation is 1.5 times the amount of RAM on your computer.
You can optimize virtual memory use by dividing the space between multiple drives and especially by removing it from slower or heavily accessed drives. To best optimize your virtual memory space, divide it across as many physical hard drives as possible. When selecting drives, keep the following guidelines in mind:
Try to avoid having a pagefile on the same drive as the system files.
Avoid putting a pagefile on a fault-tolerant drive, such as a mirrored volume or a RAID-5 volume. Pagefiles don't need fault-tolerance, and some fault-tolerant systems suffer from slow data writes because they write data to multiple locations.
Don't place multiple pagefiles on different partitions on the same physical disk drive.
To change the size of the virtual memory paging file
Open System in Control Panel.
On the Advanced tab, click Performance Options, and under Virtual memory, click Change.
In the Drive list, click the drive that contains the paging file you want to change.
Under Paging file size for selected drive, type a new paging file size in megabytes in the Initial size (MB) or Maximum size (MB) box, and then click Set.
If you decrease the size of either the minimum or maximum page file settings, you must restart your computer to see the effects of those changes. Increases typically do not require a restart.
You must be logged on as an administrator to the local computer to change the size of your computer's paging file.
To open a Control Panel item, click Start, point to Settings, click Control Panel, and then double-click the appropriate icon.
For best performance, set the initial size to not less than the recommended size under Total paging file size for all drives. The recommended size is equivalent to 1.5 times the amount of RAM on your system.
Usually, you should leave the paging file at its recommended size, although you might increase its size if you routinely use programs that require a lot of memory.
To delete a paging file, set both initial size and maximum size to zero.