title: Is there a limit to how many OpenGL rendering contexts you can create simultaneously?
body: <p>My .Net Winforms application creates three OpenGL rendering contexts in my main window, and then allows the user to popup other windows where each window has two more rendering contexts (using a splitter). At around the 26th rendering context, things start to go REALLY slow. Instead of taking a few milliseconds to render a frame, the new rendering context takes between 5 and 10 seconds. It still works, just REALLY SLOW! And OpenGL does NOT return any errors (glGetError).</p>
  
  <p>The other windows work fine. Just the new rendering contexts after a certain number slow down. If I close those windows, everything is fine -- until I reopen enough windows to pass the limit. Each rendering context has its own thread, and each one uses a simple shader. The slow down appears to happen when I upload a texture. But the size of the texture has no effect on how many contexts I can create, nor does the size of the OpenGL window.</p>
  
  <p>I'm running on nVidia cards and see this on different GPU's with different amounts of memory and different driver versions. What's the deal? Is there some limit to how many rendering contexts an application can create?</p>
  
  <p>Does anyone else have an application with LOTS of rendering contexts going at the same time?</p>