I'm using XNA but I assume the problem is analogous in DX9?
So I'm having a huge problem rendering a model that's created dynamically at runtime. It renders fine but it's creating a huge lag.
Here's the issue illustrated through a comparison:
1) Model with 10,000 vertices created in 3ds max and rendered with shader X in XNA ---> 200fps (after everything else has happened in the game)
2) Similar 10,000 vertex model constructed at runtime with a dynamic vertex buffer and rendered with shader X ---> 100fps
This is a completely unacceptable drop and I assume I'm doing something wrong. Something like minecraft would be impossible to run if this was a necessary drop. I can post my code if necessary but I'm just using the same approach used by the 3D particles sample. I've profiled the projected with NProf and all of the time is being spent in GraphicsDevice.Present()