<Table> <Tr> <Td> </Td> <Td> This article does not cite any sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (January 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article does not cite any sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (January 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> The Native Image Generator, or simply NGen, is the ahead - of - time compilation (AOT) service of the . NET Framework . It allows a CLI assembly to be pre-compiled instead of letting the Common Language Runtime (CLR) do a just - in - time compilation (JIT) at runtime . In some cases the execution will be significantly faster than with JIT . </P> <P> The Native Image Generator produces a native binary image for the current environment (i.e.; operating systems). This eliminates the JIT overhead at the expense of portability and disk space; whenever an NGen - generated image is run in an incompatible environment, . NET Framework automatically reverts to using JIT . Once NGen is run against an assembly, the resulting native image is placed into the Native Image Cache (NIC) for use by all other CLI assemblies . This makes it possible, for example, to use NGen to process CLI assemblies at installation time, saving processor time later on, when the end - user invokes the application on their system . </P>

What is native image generator (ngen.exe)
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