I am developing a game on DirectX9/10 that makes use of Hardware Instancing to draw part of the graphics. My question is, why there is such abyssal difference in speed between DX9 and DX10 on this GPU?
The DX9 one takes 0.5 ms to draw everything, The DX10 one takes 8 ms to draw everything.
I tried the same application ona Nvidia Geforce 9600M and the performance was
DX9 0.3 ms to draw everything DX10 0.3 ms to draw everything
So i'm pretty sure is not my code to have problem...Is the DX10 support for this GPU still incomplete? Can we expect some driver updates in the future? Or what? There is some other reason for this slowdown?
EDIT : Please note that the CPU usage is almost the same between DX9 and DX10. Only the times are different...this is why i'm inquiring about WHY this behaviour.
I've read about Software Vertex Processing on the Net, can it be the cause? How can i check in what mode the GPU is? and how can i force one or another mode in DX10?
Feal, to test if SW VP is better, you can enter a registry key. Do a registry search for "~3dmark.exe". You can enter the name of your .exe with a tilde in front of it as a DWORD entry and set it to 1. Then the drivers will run your app in SW VP.