Mercurial > hg > batch-feature-extraction-tool
diff Lib/fftw-3.2.1/doc/html/.svn/text-base/How-Many-Threads-to-Use_003f.html.svn-base @ 15:585caf503ef5 tip
Tidy up for ROLI
| author | Geogaddi\David <d.m.ronan@qmul.ac.uk> |
|---|---|
| date | Tue, 17 May 2016 18:50:19 +0100 |
| parents | 636c989477e7 |
| children |
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--- a/Lib/fftw-3.2.1/doc/html/.svn/text-base/How-Many-Threads-to-Use_003f.html.svn-base Wed May 04 11:02:59 2016 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,79 +0,0 @@ -<html lang="en"> -<head> -<title>How Many Threads to Use? - FFTW 3.2.1</title> -<meta http-equiv="Content-Type" content="text/html"> -<meta name="description" content="FFTW 3.2.1"> -<meta name="generator" content="makeinfo 4.8"> -<link title="Top" rel="start" href="index.html#Top"> -<link rel="up" href="Multi_002dthreaded-FFTW.html#Multi_002dthreaded-FFTW" title="Multi-threaded FFTW"> -<link rel="prev" href="Usage-of-Multi_002dthreaded-FFTW.html#Usage-of-Multi_002dthreaded-FFTW" title="Usage of Multi-threaded FFTW"> -<link rel="next" href="Thread-safety.html#Thread-safety" title="Thread safety"> -<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> -<!-- -This manual is for FFTW -(version 3.2.1, 5 February 2009). - -Copyright (C) 2003 Matteo Frigo. - -Copyright (C) 2003 Massachusetts Institute of Technology. - - Permission is granted to make and distribute verbatim copies of - this manual provided the copyright notice and this permission - notice are preserved on all copies. - - Permission is granted to copy and distribute modified versions of - this manual under the conditions for verbatim copying, provided - that the entire resulting derived work is distributed under the - terms of a permission notice identical to this one. - - Permission is granted to copy and distribute translations of this - manual into another language, under the above conditions for - modified versions, except that this permission notice may be - stated in a translation approved by the Free Software Foundation. - --> -<meta http-equiv="Content-Style-Type" content="text/css"> -<style type="text/css"><!-- - pre.display { font-family:inherit } - pre.format { font-family:inherit } - pre.smalldisplay { font-family:inherit; font-size:smaller } - pre.smallformat { font-family:inherit; font-size:smaller } - pre.smallexample { font-size:smaller } - pre.smalllisp { font-size:smaller } - span.sc { font-variant:small-caps } - span.roman { font-family:serif; font-weight:normal; } - span.sansserif { font-family:sans-serif; font-weight:normal; } ---></style> -</head> -<body> -<div class="node"> -<p> -<a name="How-Many-Threads-to-Use%3f"></a> -<a name="How-Many-Threads-to-Use_003f"></a> -Next: <a rel="next" accesskey="n" href="Thread-safety.html#Thread-safety">Thread safety</a>, -Previous: <a rel="previous" accesskey="p" href="Usage-of-Multi_002dthreaded-FFTW.html#Usage-of-Multi_002dthreaded-FFTW">Usage of Multi-threaded FFTW</a>, -Up: <a rel="up" accesskey="u" href="Multi_002dthreaded-FFTW.html#Multi_002dthreaded-FFTW">Multi-threaded FFTW</a> -<hr> -</div> - -<h3 class="section">5.3 How Many Threads to Use?</h3> - -<p><a name="index-number-of-threads-325"></a>There is a fair amount of overhead involved in synchronizing threads, -so the optimal number of threads to use depends upon the size of the -transform as well as on the number of processors you have. - - <p>As a general rule, you don't want to use more threads than you have -processors. (Using more threads will work, but there will be extra -overhead with no benefit.) In fact, if the problem size is too small, -you may want to use fewer threads than you have processors. - - <p>You will have to experiment with your system to see what level of -parallelization is best for your problem size. Typically, the problem -will have to involve at least a few thousand data points before threads -become beneficial. If you plan with <code>FFTW_PATIENT</code>, it will -automatically disable threads for sizes that don't benefit from -parallelization. -<a name="index-FFTW_005fPATIENT-326"></a> -<!-- --> - - </body></html> -