This article contains information and commonly asked questions aboutvirtual memory in Microsoft Windows.
Windows uses a dynamic virtual memory manager to handle swap fileduties. You should use the default virtual memory settings wheneverpossible. However, if you have limited hard disk space you may want toset some of the virtual memory settings manually.
In order to provide more memory to applications than is physicallypresent in the computer in the form of RAM, Windows uses hard disk spaceto simulate RAM. The amount of RAM in the computer plus the size of thepaging file (also known as the swap file) equals the total physicalmemory, or virtual memory, size. Windows uses a dynamic paging file thatremains at a size of 0K until it is needed. The paging file can grow touse all the available space on the hard disk if it is necessary. This isthe default setting for the paging file. You should use this setting ifpossible.
If you have limited hard disk space, other applications may reducethe amount of virtual memory below that needed by Windows and itsapplications. If this occurs, choose the "Let me specify my own virtualmemory settings" option button on the Performance tab of the My Computerproperty sheet. You can use this option to set a minimum and maximum sizefor the paging file. Setting this too low can result in "out of memory" errors or worse when virtual memory requirements exceed the maximum limit.
You can also choose to use no virtual memory. You should use this optiononly if there is enough RAM to meet all the needs of Windows and theapplications you run.
NOTE: The Disable Virtual Memory option is unavailable on computers with8 MB of RAM or less.
QUESTIONS AND ANSWERS
Q. In Microsoft Windows version 3.x, a temporary swap file is slower than a permanent swap file. Will letting Windows 95/98/Me set my virtual memory slow down my computer? A. No. The temporary swap file in Windows 3.x has to switch between real mode and protected mode, slowing down the computer. As Windows 95/98/Me runs only in protected mode, the swap file is as fast or faster than the permanent swap file in Windows 3.x.
Q. I compressed my hard disk with DriveSpace. Can I still select my own virtual memory settings? In Windows 3.x I cannot use a permanent swap file on a compressed drive. A. If your compressed drive is supported by a protected-mode driver, it is better to use the compressed drive for the paging file. If the compressed drive is not supported by a protected-mode driver then you must place the paging file on the host drive.
Q. How can I determine whether my compressed drive is supported by a protected-mode driver? A. At this time there are protected-mode drivers only for DoubleSpace and DriveSpace compressed drives. You can also check the IOS.INI file (if it exists) in the Windows directory to see which drives require real-mode support.