Going from 3.5 to Next - slow down

[devin]

The first images is Next set to default settings, the second is Next with the changes. The first image rendered in 3m34s, the second in 2m4.5s, a very good improvement even a little faster than the scene rendered in 3.5. No to figure out how to get that 2-7 time speed increase!

[glorybound]

My exteriors do grind to a halt with trees. I start my renders in the middle of my scene and the est. time is usually around an hour. When my buckets start hitting trees, on the outsides of my scene, it jumps to 2-3 hours.

[Muhammed_Hamed]

devin Sample rate explains the different render times for this scene really
You can reduce the render time a bit more by using max subdivs of 16.. keep the min shading rate at 16, LC samples at 500 and dynamic memory limit to 0
Now use filter type, Lancsoz and filter size of 1.5 (Not related to rendering speed, but It is what I use personally for this kind of work)
Use IR for primary GI, and use medium preset.. Change Max rate to zero and color threshold to 0.3
Personally, I don't use IR map anymore.. BF is fast enough now and you get some nice shadows and contrast out of it compared to IR.. and I don't recommend using anything below 24 for max subdivs
And I think High res renders of this scene side by side will show differences between 3.5 and Next in quality and noise patterns
The speed improvements are scene dependent, but Next was never slower than Vray 3 in my testings so far..
the 25% faster rendering as baseline is 100% correct as advertised by Chaos Group
Things like SSS, Fog, hair, refractions and GI intensive interiors with adaptive domelight show the huge speed improvements in Next (2-3 times faster than 3.6)..
Vray next GPU shows crazy speed improvements too!