title: different behavior when using different number of multicoring workers
body: <p>I am playing around a bit with my program (trying to multicore a few parts) and I've noticed the "CPU history" looks a bit different, depend on how many workers I start. 2-4 workers seems to produce a "stable" workflow, however pegging 5-8 workers produces erratic behavior (from zero to max, see pictures). I should point out that all runs started out with "smooth" max capacity (e.g. 2 cores with only 25%), and started to exhibit erratic behavior only after a minute or so.
  What's going on? I have 4 core processor, and do you think this behavior may be related to this fact?</p>
  
  <p>I hope you can see the pics.</p>
  
  <p>2 workers
  <img src="https://i.stack.imgur.com/qHsTw.jpg" alt="2 workers"></p>
  
  <p>3 workers
  <img src="https://i.stack.imgur.com/jyVeE.jpg" alt="3 workers"></p>
  
  <p>4 workers
  <img src="https://i.stack.imgur.com/gyVn4.jpg" alt="4 workers"></p>
  
  <p>5 workers
  <img src="https://i.stack.imgur.com/9lGqU.jpg" alt="5 workers"></p>
  
  <p>6 workers
  <img src="https://i.stack.imgur.com/Nubcs.jpg" alt="6 workers"></p>
  
  <p>7 workers
  <img src="https://i.stack.imgur.com/8HEsM.jpg" alt="7 workers"></p>
  
  <p>8 workers
  <img src="https://i.stack.imgur.com/r1GVJ.jpg" alt="8 workers"></p>