How to reduce compile time for unit tests with visual studio and c#

I am working on a c# project and am having an issue with running my unit tests. Specifically it seems that each time I modify o开发者_如何学JAVAne module in my source code, and then run my unit tests, Visual Studio rebuilds most if not all of my projects.

Any suggestions as to how to make this faster?

First modularize your tests.

Make sure that your libraries ore in the GAC.

Second run your code through ngen.exe (provided you don't changes your tests too much) to create a native image. Once you create a native image for an assembly, the runtime automatically uses that native image each time it runs the assembly. Put the test code image in the GAC