[レンダーステート変更ふんだん使用バージョン]
protected override void Render()
{
  long time=DateTime.Now.Ticks;
  device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, Color.White, 1.0f, 0);
  device.BeginScene();
  device.VertexFormat = CustomVertex.TransformedColored.Format;
  device.RenderState.CullMode=Cull.None;

  for(int i=0;i<50000;i++)
  {
    device.RenderState.ShadeMode=ShadeMode.Flat;
    device.RenderState.ColorWriteEnable=0;
    device.SetStreamSource( 0, vertexBuffer[i], 0);
    device.DrawPrimitives(PrimitiveType.TriangleFan, 0, 2);
    device.RenderState.ShadeMode=ShadeMode.Gouraud;
    device.RenderState.ColorWriteEnable=ColorWriteEnable.RedGreenBlueAlpha;
    device.DrawPrimitives(PrimitiveType.LineStrip, 0, 4);
  }

  device.EndScene();
  time=DateTime.Now.Ticks-time;
  Console.WriteLine("{0}",time);
}