Disabling Prefetch

5/10/2007

EWF performance can sometimes be improved by disabling Prefetch. Prefetch is a utility that is intended to improve Windows and application startup performance by loading application data into memory before it is demanded. When using EWF with a RAM overly to protect the boot volume, Prefetch is unable to persist its data from startup to startup. Under these conditions, Prefetch will attempt to compute and save new data files each time the system starts up consuming EWF resources with, potentially, no benefit.

To disable pref

  • Update the EnablePrefetcher registry key in your run-time image:

    Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters

    Name: EnablePrefetcher

    Type: REG_DWORD

    Value: 0

The EnablePrefetcher key has the following values:

0 = Disabled

1 = Application launch prefetching enabled

2 = Boot prefetching enabled

3 = Application launch and boot enabled

To disable Prefetch, set the value to 0.

  • Update the EnablePrefetcher registry key in your run-time image:

    Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters

    Name: EnablePrefetcher

    Type: REG_DWORD

    Value: 0

The EnablePrefetcher key has the following values:

0 = Disabled

1 = Application launch prefetching enabled

2 = Boot prefetching enabled

3 = Application launch and boot enabled

To disable Prefetch, set the value to 0.

See Also

Other Resources

EWF Performance Considerations
EWF Design Considerations