Just back from Blender Conf 2013 .. so nice , as usual :D
Below the slides i had prepared for the Tube project talk . Presentation was very short, so i only mentioned the tests i did on render performance of complex node trees in progressive path tracing vs. branched path tracing.
The 1st 10 slides are misc. w.i.p. images from Tube , the last ones show some comparisons between integrators , basically : branched being faster for easier cases (like absence of transmission and sss components and no dof or motion blur which require high AA ) and if setup correctly (trying to keep AA samples as low as possible)
Also the comparison is between complex node trees (= blending dirtmaps and tileables ‘live’ in the cycles material nodes) and ‘baked’ materials (= not lightbake, just ‘flattening’ the node tree to a single image per channel)
And the result is, baked shaders are much faster (circa. 150%) than complex nodetrees in progressive mode , while in branched the difference is only around 10%.
The test should be more extensive , with more data points ..but this seems to be the pattern. That’s relatively good news for shading artists wanting the flexibility and speed of setup of complex nodetrees but worried about their technical rendertime performance.
More to come on the subject, please post if you have any question.
EDIT : seems the slideshow gallery type doesn’t allow fullscreen , to see images fullsize (to read rendertimes!) click below (“more..”) to see expanded gallery with links to fullsize slides.