fft with PVM

[Mark Borgerding]

miguel_angel wrote:
> hi ,i need and algorith for the fast fourier tranform whit pvm funtions
> can somebody help me , thanks
>
>
> PD : sorry for my english

I don't know about pvm, but older versions of fftw used mpi.

(www.fftw.org)

Newer FFTW versions do not support it however. My guess why: an FFT
does not have a high enough cpu/bandwidth ratio to make it worthwhile to
distribute across multiple machines.

Example:
KISS FFT is only half as fast as fftw, but on my old machine it can
still consume 130MB of data every second with nfft=1024. That's more
than a gigabit per second.
FFTW is roughly twice as fast as KISS FFT. So if you're using FFTW, that
means you'd need 2Gb/s network I/O to feed the CPUs. That's needed on
*both* sides of the network connection!
Multiply that by dual or quad cpus, each twice as fast as my little
Athlon XP1700+. The fft of a single buffer is not a good choice for a
distributable unit of work.


I cross-posted this to comp.dsp where it may also find interested parties.

-- Mark Borgerding