[Pw_forum] Errors in parallel 3D FFT

[Lorenzo Paulatto]

On Wed, 13 Jan 2010 16:51:20 +0100, Iain Bethune  
<ibethune at staffmail.ed.ac.uk> wrote:
> Any idea what might be causing this?

Hi Iain,
are you using "vanilla" FFTW libraries or architecture optimized ones?  
(e.g. ACML, ESSL) Some high performance libraries can trade a little of  
accuracy for speed, and to be honest. I'm not even sure that perfect  
matching (whatever the definition of perfect) is guaranteed even with the  
standard open-source FFTW libraries.

best regards

-- 
Lorenzo Paulatto

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