Willi,
The reply above is correct that you cannot turn optimization on for specific files. However, there is another way to achieve what you want.
You can create a separate project that builds a static library and contains the files you want to optimize. You can include the static library built by that project in your main project. You can then turn optimization on for the static library project.
If you add the static library project to the same workspace that already contains your main project then you will be able to see all your files at the same time in the workspace tree. You can even make your main project depend on the static library project so that building the main project will automatically cause the static library project to rebuild when needed. The way project dependencies work in CVI, CVI will automatically build the configuration of the static library project (Debug, Debug64, Release, Release64) that matches the currently selected configuration of your main project. If you want to debug code in the static library project, you can just open one of those files, set a breakpoint, and run the main project and you should hit that breakpoint. You can configure project dependencies by selecting Build >> Project Dependencies.
Once you have this setup, it should behave exactly the way you wanted.
I hope this helps.
-Jeff
