The benefits / disadvantages of unity builds? [duplicate]

Solution 1:

Very similar question and good answers here: #include all .cpp files into a single compilation unit?

The summary seems to be that less I/O overhead is the major benefit.

See also The Magic Of Unity Builds as linked in the above question as well.

Solution 2:

Lee Winder posted his experiences with the Unity Builds - The Evils of Unity Builds

His conclusion is:

Unity builds. I don’t like them.