title: Measure program runtime statistically sound
body: <p>Assume I have two variants of my compiled program, <code>./foo</code> and <code>./bar</code>, and I want to find out if <code>bar</code> is indeed faster.</p>
  
  <p>I can compare runtimes by running <code>time ./foo</code> and <code>time ./bar</code>, but the numbers vary too much to get a meaningful result here.</p>
  
  <p>What is the quickest way to get a statistically sound comparisons of two command line program execution times? E.g. one that also tells me about the variance of the measurements?</p>