   DX7 : Stall in EndScene()
  We're seeing a strange problem that I'm hoping someone has seen before and might be able to help with. I've posted to microsoft's DirectX mailing list with little success, so I'm hoping to have a bit more luck here.First off, it's in DX7. Yes, it's old, but we don't have much of a choice. Second, this problem does not happen on all hardware. So far as we have been able to test, it only seems to happens with GeForce2 cards (So it might very well turn out to be a driver bug).Our frame sequence is pretty straighforward :1. Update all objects2. Display the last rendered frame (By blitting our 3D surface to the desktop)3. BeingScene4. Send render stuff5. EndSceneThe idea being that this way, the graphics hardware has the time we spend on updating objects to finish, maximizing the parallelism.The problem we are having is that on certain hardware, the call to EndScene actually stalls the CPU until all rendering is done, which makes our framerate tank.I tried moving the EndScene call to just before the blit (So, at step 1.5), but on that same hardware, the GPU sits idle until EndScene is called, so it doesn't really solve anything.Hopefully I'm not the last one working with DX7, and someone else has seen this problem :)Thanks,Patrick   