[Pw_forum] PW compilation with Threaded and MPI FFTW

[Davide Ceresoli]

sir_puding at tut.by wrote:
> Hi, All.
> 
> Is it possible to use threaded and MPI version of FFTW with espresso?
Is not that simple as just linking a different library (libfftw_threads.a)!
The MPI and threaded version of FFTW require different subroutine calls.
See e.g.: http://www.fftw.org/fftw2_doc/fftw_4.html#SEC47

> Configure script produces only -lfftw link option and i think it means
> that nonparallel version of FFTW is used. So, how RG space separation
> (on several CPU/nodes in pool) is possible in this case?
Parallel FFT is implemented in espresso. See Modules/fft_base.f90.

Davide