What if there is no reflection?

So if I crank the Diffuse level to 2 I get refliction on the ground with higher render time but if I get it down to 1 or even 0 I don't get reflection on the ground but with advantage of a lower render time, that I understood.
but what if the ground's material physically doesn't reflict the color of the robo orb? would changing those settings still have any effect on the render time?

  • Kent Trammell replied

    I suppose for the floor to not reflect the color of objects its on, it would need to be 100% black and 100% diffuse. In that case I imagine those settings wouldn't have much effect.