Re: [Discuss-gnuradio] 3DNow fir test failing under debian with latest unstable updates

[Eric Blossom]

On Mon, Aug 22, 2005 at 08:35:08AM -0400, Krzysztof Kamieniecki wrote:
> Quoting Eric Blossom <address@hidden>:
> > 
> > I'm open for suggestions as to how we should select SSE vs 3DNow.
> > Shall we benchmark the first time through and store the answer?
> > 
> I would be happy with a manual selection in a ~/.gnuradio.rc file.
> 
> simd_instruction_set={auto,none,sse,3dnow,altivec,...} 
> //auto would have the same behaviour as the current method

OK.  It could be different for each filter kernel...

> > Regarding:
> > 
> > > model name      : AMD Athlon(tm) 64 Processor 3700+
> > > stepping        : 10
> > > cpu MHz         : 797.986
> > > cache size      : 1024 KB
> > 
> > It appears that though you have an AMD64 machine, GNU Radio is
> > being compiled as a 32-bit app.  Can you send me the output of
> > uname -a and configure?
> > 
> I will do this when I get home tonight. I'm running a 32bit linux image. I 
> don't
> want to experiment with 64bit debian just yet, plus the "production" system I
> am  using for this project is a 32bit Intel processor.

You're giving up a ton of performance by not running in 64-bit mode.
The compiler has twice as many registers to work with in 64-bit mode.

> > Also, is the cpu MHz output right? 800?? Seems way low, unless you're
> > in some kind of power saving mode (which wouldn't be good for
> > benchmarking!)
> > 
> It's a compaq r3000z amd64 2.4GHz laptop (desktop replacement), I'll look into
> forcing the processor clock to maximum before running the benchmarks.

Eric