title: How to optimize QGraphicsView's performance?
body: <p>I'm developing a CAD application using Qt 5.6.2 that is required to run in cheap computers at the same time that it needs to handle thousands of items in the same scene. Because of that, I had to make a lot of experimentations in order to get the best performance. </p>
  
  <p>I decided to create this post to help others and also myself, as long as other people also contribute with more optimization tips. </p>
  
  <p>My text is still a work in progress and I may update it if I discover better techniques (or that I said something really stupid).</p>