title: Difference in opengl speed between Qt 4/5 and Opengl API
body: <p>I have read all the questions on SO that i could find about qt 4 and 5 opengl.  This one came the closest <a href="https://stackoverflow.com/questions/15671816/opengl-vs-qopengl-qtopengl-in-qt-5-differences-and-limitations">OpenGL vs QOpenGL/QtOpenGL in Qt 5: differences and limitations?</a> , I have no idea why it was closed because its a great question.  The only aspect I see it missing is the speed difference.  </p>
  
  <p>I have also read this <a href="https://qt-project.org/forums/viewthread/22921" rel="nofollow noreferrer">https://qt-project.org/forums/viewthread/22921</a>  which had a similar question, but as the back and forth about 4 vs 5, mostly discussing new features.  </p>
  
  <p>My question is, is using the built in methods of QT5 faster than making a custom widget using the opengl API directly?  If I am concerned about performance, is using QT a bad choice and there </p>
  
  <p>EDIT:</p>
  
  <p>To be a little more specific, I need to use physx, tcp/ip communication, and large numbers of quickly updating vertices and meshes.  The goal is to do this as close as realtime as possible.  Things like rendering is not a concern, but any bit of overhead from qt is damaging. (Everything is in 3D with C++)</p>