title: Good practice on optimal repartition of files in folders
body: <p>I have some files with number as names I want to put in folders on a optimized way such as about same number of files per folder et al.</p>
  
  <p>Would it be a good practice to choose the folder after the modulus of the number ? Is modulus as expensive as division? How many instructions does it takes?</p>
  
  <p>To be more precise, I would like to use the modulus of the estimated number of files's square root.</p>
  
  <p><code>Number of files &gt; 5'000'000</code></p>