<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 10 Oct 2012, at 08:37, Rustom Mody wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Hello<br><br>We are considering Erlang for a project involving significant data-processing under severe time-crunch<br><br>I am trying to understand the sentence (from <a href="http://www.erlang.org/faq/introduction.html#id49576">http://www.erlang.org/faq/introduction.html#id49576</a> )<br>
----------<br>The most common class of 'less suitable' problems is
characterised by performance being
a prime requirement <strong>and</strong> constant-factors
having a large effect on performance.<br>----------<br><br>How do I understand the '... and constant-factors…'<br></blockquote><br></div><div>For example, if the problem involves a significant sequential</div><div>component that needs to be very fast, and cannot be made </div><div>fast by distributing the work across multiple work units.</div><div><br></div><div>In some cases, even if the problem can scale, it may be the case</div><div>that Erlang is simply too slow to ever reach parity with very fast</div><div>sequential solutions. One such example is the ant colony </div><div>optimization experiment [1], where the Erlang solution did scale</div><div>well, but started off being ca 130x slower on one core than the </div><div>MLTon Standard ML solution. The fact that the Erlang solution </div><div>got 1.9x speedup with two cores then becomes rather academic.</div><div><br></div><div>[1] <a href="http://eric_rollins.home.mindspring.com/erlangAnt.html">http://eric_rollins.home.mindspring.com/erlangAnt.html</a></div><div><br></div><div>This is of course only speaking in general terms. In many cases,</div><div>small parts of performance-critical parts can be factored out and</div><div>written in e.g. C, with the rest of the application written in Erlang.</div><div><br></div><div>BR,</div><div>Ulf W</div><br><div apple-content-edited="true">
<div><div>Ulf Wiger, Co-founder & Developer Advocate, Feuerlabs Inc.</div><div><a href="http://feuerlabs.com">http://feuerlabs.com</a></div></div><div><br></div><br class="Apple-interchange-newline">
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