Editing Memory paging (section)

====Fragmentation====
{{update|section|date=July 2014}}
In the default configuration of Windows, the page file is allowed to expand beyond its initial allocation when necessary. If this happens gradually, it can become heavily [[file system fragmentation|fragmented]] which can potentially cause performance problems.<ref>{{cite web
|url         = https://technet.microsoft.com/en-us/sysinternals/bb897426
|title       = Windows Sysinternals PageDefrag
|work        = Sysinternals
|publisher   = [[Microsoft]]
|date        = November 1, 2006
|access-date  = 2010-12-20
|url-status     = live
|archive-url  = https://web.archive.org/web/20101225112753/http://technet.microsoft.com/en-us/sysinternals/bb897426
|archive-date = December 25, 2010
}}</ref> The common advice given to avoid this is to set a single "locked" page file size so that Windows will not expand it.  However, the page file only expands when it has been filled, which, in its default configuration, is 150% of the total amount of physical memory.<ref>{{cite web
|title = Page File Information
|url = https://oingo.kpt.co.id/IT/en/107-2/page-file_12799_oingo-kpt.html
|website = Oingo KPT
|access-date = 14 December 2024
}}</ref> Thus the total demand for page file-backed virtual memory must exceed 250% of the computer's physical memory before the page file will expand.

The fragmentation of the page file that occurs when it expands is temporary. As soon as the expanded regions are no longer in use (at the next reboot, if not sooner) the additional disk space allocations are freed and the page file is back to its original state.

Locking a page file size can be problematic if a Windows application requests more memory than the total size of physical memory and the page file, leading to failed requests to allocate memory that may cause applications and system processes to fail. Also, the page file is rarely read or written in sequential order, so the performance advantage of having a completely sequential page file is minimal. However, a large page file generally allows the use of memory-heavy applications, with no penalties besides using more disk space. While a fragmented page file may not be an issue by itself, fragmentation of a variable size page file will over time create several fragmented blocks on the drive, causing other files to become fragmented. For this reason, a fixed-size contiguous page file is better, providing that the size allocated is large enough to accommodate the needs of all applications.

The required disk space may be easily allocated on systems with more recent specifications (i.e. a system with 3&nbsp;GB of memory having a 6&nbsp;GB fixed-size page file on a 750&nbsp;GB disk drive, or a system with 6&nbsp;GB of memory and a 16&nbsp;GB fixed-size page file and 2&nbsp;TB of disk space). In both examples, the system uses about 0.8% of the disk space with the page file pre-extended to its maximum.

[[Defragment]]ing the page file is also occasionally recommended to improve performance when a Windows system is chronically using much more memory than its total physical memory.<ref>{{cite web
|title = What Does Defragging Do?
|url = https://www.hp.com/us-en/shop/tech-takes/what-does-defragging-do
|website = HP Tech Takes
|publisher = Hewlett-Packard
|access-date = 14 December 2024
}}</ref> This view ignores the fact that, aside from the temporary results of expansion, the page file does not become fragmented over time. In general, performance concerns related to page file access are much more effectively dealt with by adding more physical memory.