Numpy will perform a parallelized calculation when using one of the underlying BLAS routines, if you have the appropriate libraries installed on your machine. S

Numpy will perform a parallelized calculation when using one of the underlying BLAS routines, if you have the appropriate libraries installed on your machine. So to take advantage of your cores, try to write the calculation as a call to a linear algebra function. Loops or expressions with arithmetic operators as in your example will run on one core. Or, just use Julia.