Several days ago i found an interesting demo piece which was written in opengl. it was a dynamic-created tunnel. so i decided to rewrite it with directx and i made it(vc++ 6.0). but the thing annoying is that the framerate is only 26 much lower than the 76 of its original opengl version(delphi). this thing also cause me to think why the game cs is much faster when using opengl and the texture quality is also better. i dont want to give up using directx but can here anyone explain why directx is slower in many ways? and how can i make it faster by using directx(at least as fast as in opengl)? thank you. 1.the tunnel has 32x12x4 vertices and 32x12x2 faces, 2.the vertex format is {x, y, z, diffuse, u, v} 3.all vertices will be updated every frame. /// Methods Intro Starts here Method 1 : Using a mesh 1. create a mesh with apporiate face number and vertex number. (using D3DMESH_WRITEONLY Flag, and 'mixed-vertex-processing' used when create the direct3d device) 2. optimize the mesh in place 3. call lockVertexBuffer every frame and fill in with new updated vertex info then unlockVertexBuffer. drawSubet(0) (only one texture applied) Method 2 : using DrawPrimitive 1. create a vertex buffer with required vertex number 2. call lock method on the vertex buffer each frame and fill in new vertex info, and unlock the buffer, then SetStreamSource, DrawPrimitive method 3 : using Transformed vertex same as method 2, but using DrawPrimitiveUp /// Intro Ends here thats all i have used to draw the tunnel, nothing special really. and all three methods i get a framerate of 26, fullscreen or windowed. [edited by - Pet123 on January 29, 2003 12:36:52 PM]

The speed of DX or GL is greatly dependant on your video card drivers.

That said if your seeing a preformance decrease like that I''d suggest that you are doing something you weren''t supposed to do. Examples of this would be doing some rendering ops out of order. Check your code and make sure your not using vsync.

Be sure you are compiling to Release mode and using the retail version of DirectX. If you have been using the debug versions, you should see a increase in performance after the switch.