Windows Page Files and Virtual Memory

What is Page File?

Page files is a file that stored in the file system and work as virtual memory of the system. It can load data in to RAM and store data from RAM. Actually this is an extension to the RAM. In windows operating systems this file named as pagefile.sys.

How Page File Works?

When you have limited physical RAM, computer can save some data into the page file. When you are working with an application program, RAM stores temporary data in it, which is needed by the application program. Because the program needs frequent modifications to those data stored in the RAM. this happens continuously while you are using the program. But if you stop working with that software for a significant amount of time, the data related to that program on the RAM that hasn't been used recently will be sent to the page file. Then the computer can read those data from the page file when needed. However virtual memory is always being used. When you load more programs in to the computer's memory, the Operating System moves some data from RAM to the page file.

Page Files and System Performance.

When you are open new programs, there should be sufficient amount of memory available in the RAM for that programs. So Operating System will examine recently unmodified data in the RAM and send them in to the page file. After moving data into the disk RAM can allocate memory for newly opened programs. So your new program will work without trouble.

But moving data from RAM to the physical disk and load data from the page file into the RAM is slower process. because Read/Write speed of hard disks are significantly slower than the RAM. So you will experienced some slowness while changing application usage. Because it take some time to transfer paged data to the RAM.

What is the recommended page file/virtual memory size?

Size of the page file depends on the installed RAM of the machine. By default, windows page file size is 1.5 amount of the RAM. For example if you have 1GB of RAM, you may need (1.5 x 2=3) 3GB for the page file. But when the system has more RAM, the size of page file decrease. If you have enough RAM installed, you may not require page files.

Basically page file size is controlled by the Operating System. Windows can automatically manage page file size for all drives. There are three values for the system page file size. They are

• Minimum allowed
• Recommended
• Currently allocated

If you have 2GB of RAM

above values looks like 16MB, 2863MB, and 1909MB respectively. By default drive C stores the paging file. Also you can set custom page file sizes for all drives in your computer. Also you can disable the page files. You can configure system page files using Advance System Settings.



Setting multiple page files on each partition may reduce perormance of the system. Also you can set page files in a drive which is not the OS installed (system drive). This can gain some added performance. Disabling virtual memory may occur system errors and windows might not record details of the errors. Page files are required to get full memory dump. Memory dump helps to analyze some errors after system failure and useful for debugging information.

Is it good idea to disable page files?

Actually disable the virtual memory page files is not a good idea. Because it can cause crash your system. Some programs need more memory. If you use Photoshop , other image editing software or video editing software, definitely they need more RAM. If your system runs out of RAM, System cannot swapped out of RAM in to the page files. So your will stuck or there can be unexpected system crashes. So it is a not good idea to disable the virtual memory of your computer.