title: Why is copy slower than move?
body: <p>I had a big file that I'm moving about. The normal protocol in the lab is to copy it somewhere and then delete it. </p>
  
  <p>I decided to change it to mv.</p>
  
  <p>My question is, why is mv so much faster than cp?</p>
  
  <p>To test it out I generated a file 2.7 GB in size.</p>
  
  <pre><code>time cp test.txt copy.txt
  </code></pre>
  
  <p>Took real   0m20.113s</p>
  
  <pre><code>time mv test.txt copy.txt
  </code></pre>
  
  <p>Took real   0m12.403s.</p>
  
  <p><strong>TL;DR</strong> mv was almost twice as fast as copy. Any explanations? Is this an expected result?</p>
  
  <p><strong>EDIT-</strong> </p>
  
  <p>I decided to move/copy the folder to a destination other than the current folder. </p>
  
  <pre><code>time cp test.txt ../copy.txt 
  </code></pre>
  
  <p>and</p>
  
  <pre><code>time mv test.txt ../copy.txt
  </code></pre>
  
  <p>This time cp took 9.238s and mv took only 0.297s. So not what some of the answers were suggesting.</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>The answers are right. When I tried to <code>mv</code> the file to a different disk on the same system, <code>mv</code> and <code>cp</code> took almost the same time.</p>