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Disabling Prefetch

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 compute and save new data files each time the system starts up consuming EWF resources with, potentially, no benefit.

To disable prefetch

  • 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

EWF Performance Considerations | EWF Design Considerations

Last updated on Wednesday, October 18, 2006

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