I implemented the “Blinn-Phong model” lighting model from the lighthouse:
verbatim (ie, I didn’t add any code to it)*, which according to them this is the same algorithm used by the fixed pipeline. And it does look identical.
However, when I turn the shader off:
it runs 8-10% faster (frame rate goes from mid 1300’s to mid 1400’s).
I haven’t really seen anyone claiming that shaders provide higher performance, just greater tweaking power.
I suppose this loss of speed is card/driver specific. Is it usually that much?
*I did optimize it slightly by removing “normalize” from the normal computation, since my normals are already unit length.