V4 Documentation

Instrumentation Mode

Solution-level NCrunch configuration setting Introduced: v4.0
Removed: v4.9
Default Value: Default
ID/Tag in config file: InstrumentationMode


This setting controls the strategy used by NCrunch for manipulating and analysing an assembly after it has been built.

As of NCrunch v4.9, this setting no longer exists. All versions of NCrunch v4.9 and up now use the Optimised mode. Legacy mode is no longer available.

Available Options

  • 'Default' - The engine will use the default strategy for processing assemblies. Currently, the default strategy is 'Legacy'. This will change in a future version.
  • 'Legacy' - The engine will process assemblies using the old system utilised by all versions of NCrunch prior to V4.
  • 'Optimised' - The engine will process assemblies using the new system introduced in NCrunch V4. This system operates significantly faster than the legacy mode.


The new optimised instrumentation mode is intended to completely replace the legacy mode. Eventually, the legacy instrumentation mode will be removed from NCrunch entirely.

You should use the new optimised mode unless you are experiencing problems with it. Please report any problems experienced to make sure we can resolve them before the legacy mode is removed from the product (along with this configuration setting).

Although this is technically considered a solution-level setting, it can also be applied at project level when NCrunch's complex configuration mode is enabled.

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