Increase File System Cache Size in Vista - Boost Performance

Optimizing Windows Filesystem Cache for Enhanced Performance

A common question arises regarding Windows' limitations in customizing the filesystem cache size. Consider a laptop equipped with a slower hard drive but possessing ample system memory. Shouldn't it be possible to leverage that memory to accelerate hard drive access speeds?

A relatively obscure adjustment exists that allows users to instruct Windows to allocate more cache to the NTFS pool. This modification has the potential to improve performance, particularly on systems that frequently open and close numerous files, such as the one used for testing.

Microsoft’s official documentation clarifies the impact of this setting:

Increasing the amount of physical memory doesn't automatically translate to a larger allocation of paged pool memory for NTFS. However, setting memoryusage to 2 effectively raises the limit on paged pool memory. This can lead to performance gains if your system is consistently opening and closing many files within the same set, and isn't already heavily utilizing system memory for other applications or caching processes. Conversely, if substantial system memory is already dedicated to other tasks or caching, increasing the NTFS paged and non-paged pool memory limit may reduce available pool memory for other processes, potentially diminishing overall system performance.

Implementing the Change via Command Line

The following steps outline how to modify the filesystem cache using the command line interface. Initial testing will be conducted, and feedback from readers is highly encouraged. It’s important to note that no benchmarks have been performed yet to definitively confirm performance improvements.

First, open a Command Prompt window with Administrator privileges. This can be achieved by right-clicking the Start button and selecting "Run as administrator," or by typing "cmd" into the Start menu search box and pressing Ctrl+Shift+Enter.

To increase the cache setting, execute this command:

fsutil behavior set memoryusage 2

To determine the current cache setting, use this command:

fsutil behavior query memoryusage

To revert to the default cache setting, employ this command:

fsutil behavior set memoryusage 1

Remember that altering these less-documented settings carries inherent risks. Proceed with caution and at your own discretion. A system reboot is typically required for the changes to take effect.

Adjusting the Cache Through Registry Modification

Alternatively, the filesystem cache can be adjusted by modifying a registry parameter. Open the Registry Editor (regedit.exe) via the Start menu search or run box.

Navigate to the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem