I try to render in cycles the most basic scene: A cube, a plane, a sun and a camera. No textures, no materials, no additional layers, no nothing. 128 samples take 46 seconds.
I tried to change +/- all parameters described in Youtube etc. to increase render-speed and nothing changed (45.6 to 47 secs for 128 samples). I render on CPU since I have no GPU. I changed:
-Sun max bounces
-Render dimensions border active
Within Blender 2.78a, the only parameter to speed up is Branched Path Tracing; set to 4 AA samples, rendering takes 2 secs, but the result is BAD.
In Blender 2.79 the same scene takes 37 instead of 46 secs.
Is it normal that changing parameters does not affect render time?
Many thanks upfront to all of you smart guys!