title: Performance Issues with SharpDX and D3DImage
body: <p>I have a control that uses D3DImage to host a SharpDX DirectX9 surface and allows use to pan, zoom, and interact with world objects and the result is really awesome.  Performance is actually an amazing consistent 60fps EXCEPT when the window is minimized and brought back up or the user locks and then unlocks the screen.  When the window regains focus the fps drop to about 25-30fps.  I can "fix" the issue by unloading and loading the control back into its container and then BOOM, 60fps.</p>
  
  <p>I call the main render function using a DispatcherTimer set at 10ms.  Before, I was using the CompositionTarget.Rendering event but performance wasn't as good as using the DispatcherTimer.  I fairly certain that I'm handling lost resources correctly.  Any ideas about these missing frames per second?</p>
  
  <p>EDIT:  <a href="http://www.gamedev.net/topic/613659-c-dx9-slow-down-after-losing-window-focus/" rel="nofollow">I am having this same exact problem</a>.  Unfortunately, doing an automatic device reset doesn't fix the issue but if I have a button that executes the same reset method then my fps goes back to normal.</p>