ADI distributes a version of make.exe that was built FIFTEEN YEARS AGO. Parallel builds do not work because this version of make.exe doesn't properly honor the parallel build flags. You can hack around this using makefile.defs, but the build output is all scrambled, making it difficult to figure out exactly what the errors are in your compile, because this version of make.exe doesn't have the feature to keep the output in sync.
Do yourself a big favor and go find a modern version of GNU make.exe. The only place I could find it was in the Chocolatey distribution.
After installing Chocolatey and typing “choco install make”, I pulled make.exe out of C:\ProgramData\chocolatey\lib\make\tools\install\bin and copied over the make.exe in the root of the CCES folder. I then went into each of my projects in the “C/C++ Build” section and set “Enable parallel build” on the Behavior tab. I then added the “-O” flag (output sync) to the Build command on the Builder settings page. Wow oh wow! My ARM project (with FreeRTOS) builds in 9 seconds, my Sharc projects build in 17 seconds. And the “-O” flag insures the output log isn’t all messed up. It is great, give it a try!