Re: Weired GNURADIO Performance


#1

Hi,

On Sat, 5/2/09, Andrew L. removed_email_address@domain.invalid wrote:
I can speculate: some versions of Ubuntu (i.e. all the ones
I’ve actually looked at) seem to build fftw without SSE/SSE2.

–Andy

Do FFTW have a function we can use to read if it is using SSE/SSE2?. If
exist, we can add a small program to gnuradio to warn about the missing
of it.

Best Regards,

Firas


#2

Firas A. wrote:

Do FFTW have a function we can use to read if it is using SSE/SSE2?. If exist, we can add a small program to gnuradio to warn about the missing of it.

I think there is a function for that, but since I couldn’t remember it,
I went to fftw.org and I found this:

“SSE, AltiVec, and MIPS PS only work with |–enable-float| (above),
while SSE2 only works in double precision (the default). The resulting
code will /still work/ on earlier CPUs lacking the SIMD extensions (SIMD
is automatically disabled, although the FFTW library is still larger).”

The default fftw is using double precision, but I have a feeling that
the build- wiki for gnuradio sugested single- precision…

//Mattias