I have a Visual Studio 2008 C++ project that has support for using multiple CPUs/cores when compiling. In the VCPROJ file I see this:

```
<Tool
    Name="VCCLCompilerTool"
    AdditionalOptions="/MP"
    ...

```

I can't find where that was turned added via the IDE and I want to set up another project that uses all of my cores during compilation.

I found tons of references to the [MSDN /MP page](http://msdn.microsoft.com/en-us/library/bb385193.aspx) but that is for using the command line; I have yet to find any references to setting that with the IDE. How do I do that?

EDIT: To clarify, the two projects are completely separate and are not in the same VCPROJ file. I wanted to turn on support for multiple cores during the C++ compilation phase.