title: CPU usage is higher than expected to be possible (over 200% with a total of two cores)
body: <p>Correct me if I'm wrong, but based on answers to <a href="https://stackoverflow.com/questions/44179820/top-command-how-come-cpu-in-process-is-higher-than-in-overall-cpu-usage-percen">this question</a> and <a href="https://www.quora.com/What-does-100-CPU-utilization-mean" rel="nofollow noreferrer">this question</a>, I understand that the percentage of CPU used can easily go up to <code>100 * number of processors * number of cores per processor</code> without affecting performance too badly; <em>e.g</em> if I have one processor with two cores, my CPU usage should be able to go easily to 200%.</p>
  
  <p>I just checked with <code>top</code> while training a small neural network in Python / <a href="https://en.wikipedia.org/wiki/TensorFlow" rel="nofollow noreferrer">TensorFlow</a>, and Python is consistently using over 300% of my single, dual core processor. </p>
  
  <p>I have not been noticing any poor performance in any other applications. How is this possible?</p>
  
  <p><a href="https://i.stack.imgur.com/jnGbK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jnGbK.png" alt="MacBook Pro specifications"></a></p>
  
  <p><a href="https://i.stack.imgur.com/Rq0Vz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Rq0Vz.png" alt="Top"></a></p>