Virtual Memory Configuration in Windows 7

In a default installation, Windows creates the page file in the root folder on the same drive that holds the Windows system files. The size of the page file is determined by the amount of RAM in the system.

By default, the minimum size on a 32-bit (x86) system is 1.5 times the amount of physical RAM if physical RAM is less than 1 GB, and equal to the amount of physical RAM plus 300 MB if 1 GB or more is installed.

The default maximum size is three times the amount of RAM, regardless of how much physical RAM is installed. On a PC with a processor that supports Physical Address Extension (PAE)—which is to say, on any PC that is capable of running Windows 7—the maximum size of the page file is 16 TB.

We can see the page file in a Windows Explorer window if we configure Windows to show hidden and system files; look for Pagefile.sys in the root of the system drive.

To see the current configuration of the system’s virtual memory, open the System dialog box in Control Panel and click the Advanced tab. Or, for a handy undocumented shortcut, click Start, type systempropertiesadvanced (with no spaces), and press Enter.

Under the Performance heading, click Settings. In the Performance Options dialog box, click the Advanced tab. And under the Virtual Memory heading, click Change.

By default, Windows creates a single page file and manages its size. The Currently Allocated number near the bottom of the dialog box shows how large the file is.

If conditions on the system change (say we run an unusually large assortment of memory-intensive applications), Windows might increase or even decrease the size of the page file. All this happens without intimation as long as you leave the “Automatically Manage Paging File Size For All Drives” option selected.

If we don’t want Windows to automatically manage the page file, you have the following options:

Ø We can move the page file to a different volume if you have more than one volume.

Ø If we have more than one volume, we can establish more than one page file.

Ø For any page file, we can choose between System Managed Size and Custom Size.

Ø If we choose Custom Size, we can specify an initial size and a maximum size.

Ø We can remove a paging file from a volume by selecting the volume and choosing No Paging File. (In fact, we can do this to get rid of all paging files, although doing so is not recommended, even on systems with a lot of RAM.)

Should you get involved in managing the page file?

If we have more than one physical disk, moving the page file to a fast drive that doesn’t contain Windows system files is a good idea. Using multiple page files split over two or more physical disks is an even better idea, because your disk controller can process multiple requests to read or write data concurrently.

If we have a single hard disk that contains volumes C, D, and E, splitting the page file over two or more of these volumes, might actually make your computer run more slowly.

If we are short of hard disk space, we might consider setting a smaller initial page file size. Monitor peak usage levels over time; if the peak is well below the current page file size, we can consider reducing the initial size to save disk space.

On the other hand, if we’re not short of disk space, there’s nothing to be gained from doing this and you might occasionally overload your custom settings, thereby degrading the performance of our system.

Should we enlarge our page file?

Most users won’t need to do this. But we might want to keep an eye on the green line in the Memory chart on the Overview tab of Resource Monitor. If that line is spiking off the top of the graph a great deal of the time during normal work, we might consider increasing the maximum size of our page file.

Note that we should disregard page file spikes and disk activity in general that takes place while we’re not actually working. This is likely to be the result of search indexing, defragmentation, or other background processes and does not indicate a problem with your actual work performance.