title: glFinish() vs glFenceSync() + glClientWaitSync()
body: <p>Is there a difference between running</p>
  
  <pre><code>glFinish()
  </code></pre>
  
  <p>and running</p>
  
  <pre><code>glFenceSync(...)
  glClientWaitSync(...)
  </code></pre>
  
  <p>with a big timeout?</p>
  
  <p>What I'm trying to do: I run a pipeline of OpenGL commands, and I want to time how long each command takes. Without any of the above commands, everything will be pipelined / buffered, and it looks as thought the last command takes all processing time.</p>
  
  <pre><code>timer start
  
  Run Opengl part 1
  
  sync / glFinish
  timer measure
  
  Run Opengl part 2
  
  sync / glFinish
  timer measure
  
  ...
  </code></pre>
  
  <p>So I'm trying to figure out how to best measure the "speed" of the individual parts without influencing too much the overall runtime.</p>