title: Sortable,js performance is very slow
body: <p>Hello everybody and thanks of looking into my issue.</p>
  
  <p>To better describe the problem I have - I created this very short <a href="http://quick.as/egwvtbvp7" rel="nofollow">screen cast</a></p>
  
  <p>I am using grid of cards as displayed in the screencast, and when I try to arrange them they are so slow and respond with lag.</p>
  
  <p>If, however, I try to use sortable inside of each card performance is normal. I have no other js functions running besides sortable at the time of dragging and dropping. I also don’t have any hidden elements as I saw that as a solution for sortable slow performance in a lot of cases. I couldn’t find any relative  example to solve this issue and I have attached short screen cast to better show my problem.</p>
  
  <p>Cards are unordered list elements inside the main ul with class <code>.exercises</code> so I have this in main jquery page:</p>
  
  <pre><code>$('.exercises').sortable();
  </code></pre>
  
  <p>and to move things around inside the card (for testing)</p>
  
  <pre><code>$('.exercises li').sortable();
  </code></pre>
  
  <p>Do any of you have any suggestion how to sort this problem as it really get annoying and it has been couple of days with no positive results.</p>
  
  <p>Let me know if you need me anything else to provide in case I forgot. Thanks in advance for your time and help.</p>