I must admit (maybe i'm wrong) that A2 and A3 were faster but a lot buggy than the recent dailies, for example the red sofa render in corona home took me this time without using noise reduction tool and it was rendered with the A3 i think, i reopened with the new dailies and i see the floor reflection got noise a lot more than before if i remember and having the same rendertime it still got some noise on it... I repeat maybe i'm wrong but this is what i see comparing to the speed of the A3 and A2.
Yes, corona lost a lot of "brute force power" in the last few versions. This was necessary to facilitate the advanced fake/shading/scaling/... algorithms. As a result, some scenes might render slower, maybe by a factor of up to 50%. But this was necessary to
1) implement algorithms that allow rendering of scenes that could not be done at all before
2) to be able to render fast some scenes that tool extremely long time before. In other words, even though generally it is a little bit slower, there are many scenes where new version is 10 times faster - motion blur, lots of lights, ...
Anyways, I will improve the speed in the future versions by implementing some smart stuff like progressivity and even better light sampling ;)
Here is my scene with settings.. I let it render for about 20 minutes.
To optimize:
1) use secondary GI solver HD cache, always for interiors
2) do not use any artificial lighting rigs. Only environment light and scene emitters like lamps, but not invisible lights in windows
3) add portals for an extra boost
3. You should ALWAYS use portals in your window holes.
Nope, they still remain optional. There are even situations where they will slow down the rendering a bit (huge windows, very dynamic HDRI)
