You can speed up the compilation on a multi-core computer. By default, when you build your project with Qt Creator, you use only one job (therefore, only one core). But make supports compilation with multiple jobs. You can use the make -j N option to allow N jobs at once. Do not forget to update your packaging scripts!
If you build your project from Qt Creator, you can set this option from Projects | Build Steps | Make. Click on Details, and in the Make arguments field, put the value -j 8 to allow for eight jobs during the compilation, as shown in the following screenshot:
