When the XML Serializer Generator is not used, a XmlSerializer generates serialization code and a serialization assembly for each type every time an application is run. To improve the performance of XML serialization startup, use the Sgen.exe tool to generate those assemblies the assemblies in advance. These assemblies can then be deployed with the application.
The XML Serializer Generator can also improve the performance of clients that use XML Web service proxies to communicate with servers because the serialization process will not incur a performance hit when the type is loaded the first time.
These generated assemblies cannot be used on the server side of a Web service. This tool is only for Web service clients and manual serialization scenarios.
If the assembly containing the type to serialize is named MyType.dll, then the associated serialization assembly will be named MyType.XmlSerializers.dll.