1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Performance</title> 5<link rel="stylesheet" href="../math.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../index.html" title="Math Toolkit 2.12.0"> 8<link rel="up" href="../overview.html" title="Chapter 1. Overview"> 9<link rel="prev" href="threads.html" title="Thread Safety"> 10<link rel="next" href="building.html" title="If and How to Build a Boost.Math Library, and its Examples and Tests"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="threads.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="building.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="math_toolkit.perf_over1"></a><a class="link" href="perf_over1.html" title="Performance">Performance</a> 28</h2></div></div></div> 29<p> 30 By and large the performance of this library should be acceptable for most 31 needs. However, often the library has to make a choice whether to be accurate 32 or fast and by default it chooses accuracy over speed. If you would rather 33 have fast rather than fully accurate routines, then refer to the <a class="link" href="../perf.html" title="Chapter 22. Performance">performance 34 section</a> for information and examples on how to achieve this. 35 </p> 36<p> 37 In terms of the algorithms used, this library aims to use the same "best 38 of breed" algorithms as many other libraries: the principle difference 39 is that this library is implemented in C++ - taking advantage of all the abstraction 40 mechanisms that C++ offers - where as most traditional numeric libraries are 41 implemented in C or FORTRAN. Traditionally languages such as C or FORTRAN are 42 perceived as easier to optimise than more complex languages like C++, so in 43 a sense this library provides a good test of current compiler technology, and 44 the "abstraction penalty" - if any - of C++ compared to other languages. 45 </p> 46<p> 47 The three most important things you can do to ensure the best performance from 48 this library are: 49 </p> 50<div class="orderedlist"><ol class="orderedlist" type="1"> 51<li class="listitem"> 52 Turn on your compilers optimisations: the difference between "release" 53 and "debug" builds can easily be a <a class="link" href="getting_best.html" title="Getting the Best Performance from this Library: Compiler and Compiler Options">factor 54 of 20</a>. 55 </li> 56<li class="listitem"> 57 Pick your compiler carefully: <a class="link" href="comp_compilers.html" title="Comparing Different Compilers">performance 58 differences of up to 8 fold</a> have been found between some Windows 59 compilers for example. 60 </li> 61<li class="listitem"> 62 Disable internal use of <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code>, this will reduce accuracy but typically 63 yield a 2x speedup on modern x64 hardware/compilers. 64 </li> 65</ol></div> 66<p> 67 The <a class="link" href="../perf.html" title="Chapter 22. Performance">performance section</a> contains more information 68 on the performance of this library, what you can do to fine tune it, and how 69 this library compares to some other open source alternatives. 70 </p> 71</div> 72<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 73<td align="left"></td> 74<td align="right"><div class="copyright-footer">Copyright © 2006-2019 Nikhar 75 Agrawal, Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, 76 Hubert Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Matthew Pulver, Johan 77 Råde, Gautam Sewani, Benjamin Sobotta, Nicholas Thompson, Thijs van den Berg, 78 Daryle Walker and Xiaogang Zhang<p> 79 Distributed under the Boost Software License, Version 1.0. (See accompanying 80 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 81 </p> 82</div></td> 83</tr></table> 84<hr> 85<div class="spirit-nav"> 86<a accesskey="p" href="threads.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="building.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 87</div> 88</body> 89</html> 90
