Re: [Discuss-gnuradio] [Fwd: [FFTW-announce] FFTW 3.2-alpha2 is available, Cell support, MPI]

[Robert McGwier]

Essentially I disagree with everything Martin says here.

The 3.X support of FFT'w from FFTW is completely transparent to the end 
user for everything we are doing since the API on 3.1 and 3.2 are 
identical.  You do a plan,  you execute by passing the plan.  About the 
only thing that "knows" you are running a K7 or a Cell is fftw?-wisdom. 
 So if you need K7 support, don't upgrade from FFTW 3.1.2  and your 
program will not know the difference.  You will because your CPU load 
will go down.

I am really glad we use floats in our processing.  The double support on 
the Cell is HORRIBLE.

Bob



Martin Dvh wrote:
> Matt Ettus wrote:
> > This bodes well for cell support...
> Cell support is very very nice.
>
> What I don't like is:
> > * Removed k7 support, which only worked in 32-bit mode and is
> >  becoming obsolete.  Use --enable-sse instead.
>
> Older athlon processors (Thunderbird, duron) don't support SSE, they only 
> support 3dnow.
> And there are still a lot of these around. ( I only upgraded from one of these 
> a few moths ago)
>
> So for older non-SSE athlons, we need to support the current FFTW release.
> For Cell support we need to support the next fftw release.
>
> But I don't think it is nice to support multiple versions, especially if you 
> want to use the new features of the later release.
>
> I sent a mail to the FFTW guys about this, I hope they reconsider and just keep 
> in the 3dnow code.
>
> Greetings,
> Martin


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