GeForce FX 5800 and 5800 Ultra run at 8 pixels per clock for all of the following:We will unpack this statement for you shortly, but it appears Fraud at The Inq got this one right.
a) z-renderingFor advanced applications (such as Doom3) *most* of the time is spent in these modes because of the advanced shadowing techniques that use shadow buffers, stencil testing and next-generation shaders that are longer and therefore make the apps "shading-bound" rather than "color fill-rate" bound.
b) stencil operations
c) texture operations
d) shader operations
Only color+Z rendering is done at 4 pixels per clock, all other modes (z, stencil, texture, shading) run at 8 pixels per clock.
The more advanced the application, the less percentage of total rendering is color, because more time is spent texturing, shading and doing advanced shadowing/lighting.