Re: [Discuss-gnuradio] PS3 - gcell_fft

[Eric Blossom]

On Wed, Jan 27, 2010 at 11:36:14AM +0100, Thilo Mönicke wrote:
> Hi,
> 
> I tried to set up a little Testprogram for the PS3 which should show
> the advantage of the Power PC structure. For that, the program should
> calculate 10000 FFTs and take the time. Unfortunately this program is
> much slower as a same program running at a GPP. With the tool spu-top
> I verified that all SPUs are working...
> 
> Do you have any idea how I could speed up my program?

Currently, the break even point is higher than 1024 points due to
the overhead to get to the SPEs and back.

Try 16384 points :-)

Eric


> Here is my Python-code (only the intresting part...):
> 
> class BenchmarkFFT(gr.top_block):
>     def __init__(self):
> 
>         ph = 
> gcell.program_handle_from_filename("/home/moenicke/gnuradio-3.2.2/gcell/lib/spu/gcell_all")
>       opts = gcell.jm_options(ph,0)
>         self.mgr = gcell.job_manager(opts)
>         gcell.set_singleton(self.mgr)
> 
>         gr.top_block.__init__(self)
> 
>         fft_len=1024
>         n_ffts=10000
> 
>       src = gr.noise_source_c(gr.GR_GAUSSIAN, 1.0)
>               head = gr.head(gr.sizeof_gr_complex, fft_len * n_ffts)
>       s2v = gr.stream_to_vector(gr.sizeof_gr_complex, fft_len)        
>       fft= gcell.fft_vcc(fft_len, True, [])   
>       sink = gr.null_sink(gr.sizeof_gr_complex * fft_len)
> 
>         self.connect (src, head, s2v, fft, sink)
>       
> reguards
> 
> Thilo
> 
> @Eric: thank you for your last answer, it was a big help for me ...