Windows 7 / Getting Started

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Optimize Virtual Memory and Cache Settings

One of the most frustrating and irritating things about Windows is the way that it can seize up for several seconds with seemingly random, pointless disk activity. One of the causes of this behavior is the way Windows handles disk virtual memory by default.

Normally, Windows loads drivers and applications into memory until it's full, and then starts to use part of your hard disk to "swap" out information, freeing up more memory for higher-priority tasks. The file that Windows uses for this type of "virtual memory" is the paging file (a.k.a. swap file), pagefile.sys, and it is stored in the root folder of your Windows drive.

Because your hard disk is so much slower than your physical memory, the more swapping Windows has to do, the slower your computer gets. This is why adding more memory speeds up your PC: it reduces Windows' appetite for virtual memory. But regardless of the amount of installed physical memory in your system, there are always things you can do to improve virtual memory performance.

Windows' defaults here are rather conservative and can fortunately be modified for better performance. It's important to realize, though, that some experimentation may be required to achieve the best configuration for your setup. Different hardware, software, and work habits require different settings; those with ample hard disks, for instance, can afford to devote more disk space to virtual memory, while others may simply wish to use this procedure to place a cap on the disk space Windows is allowed to consume.