Compiling more than one file at once?

[ninja9578]

I have 4 cores, it's frustrating for me to see cc1plus.exe running at 25%.  Is there any way to have Code::Blocks / MinGW compile multiple files at once, I have a project that from time to time requires a complete rebuild.  It's 500 source files and takes the better part of an hour to compile fully.

[Jenna]

"Settings -> Compiler and debugger... -> Global compiler settings -> Other settings -> Compiler-independent options -> Number of processes for parallel builds".

I use 3 processes on a core2duo and that works fine.