Re: [Discuss-gnuradio] Large FFTs

[Juha Vierinen]

Hi,

Gnuradio uses FFTW, which as a pretty nice benchmark page [1]. If we
look at the results for a fairly new intel processor, we see that a
262144 point FFT can be computed with about 9 GFLOPS speed, which
means that a 262144 point FFT should be done in less than 3 ms.

[1] http://www.fftw.org/speed/

I have been using 65 kpoint FFTs for real-time spectral analysis with
USRP1 and USRP2 with no problems.

juha

On Mon, Aug 23, 2010 at 08:00, Thomas Hobiger <address@hidden> wrote:
> We are considering to purchase a USRP2 + a DBSRX board in order to utilize
> it for some GPS stuff. Thus it would be interesting to know what's the
> maximum supported (implemented) FFTs size. I have checked the old
> discussions, but there's nothing really conclusive. What we are looking for
> is something larger than 16K FFT points.
> Maybe someone has experiences with such large FFTs and how they perform
> (Flops or FFTs per second)?
>
> Best regards,
>  Thomas Hobiger
>
> --
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> Dr. Thomas Hobiger
> Space-Time Measurement Project
> Space-Time Standards Group
> New Generation Network Research Center
> National Institute of Information and Communications Technology
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