To use the compiled de stepper and bounds checks use: (cd bumps/dream && cc compiled.c -I ../../Random123/include/ -O2 -fopenmp -shared -lm -o _compiled.so -fPIC) Note: OS/X clang doesn't support OpenMP: (cd bumps/dream && cc compiled.c -I ../../Random123/include/ -O2 -shared -lm -o _compiled.so -fPIC) This only works when _compiled.so is in the bumps/dream directory. If running from a pip installed version, you will need to fetch the bumps repository: $ git clone https://github.com/bumps/bumps.git $ cd bumps Compile as above, then find the bumps install path using the following: $ python -c "import bumps.dream; print(bumps.dream.__file__)" #dream/path/__init__.py Copy the compiled module to the install, with the #dream/path printed above: $ cp bumps/dream/_compiled.so #dream/path There is no provision for using _compiled.so in a frozen application. Run with no more than 64 OMP threads. If the number of processors is more than 64, then use: OMP_NUM_THREADS=64 ./run.py ... I don't know how OMP_NUM_THREADS behaves if it is larger than the number of processors.