That was in the Corona Render group, you'll need to be a member to see the post I believe -
https://www.facebook.com/groups/183831411996004/permalink/493796174332858/The main points about speed are:
- Speed comparisons in the blog are given against 1.6.1 rather than 1.6.3, since 1.6.3 has the DMC sampler in it (which will benefit you in cases like single HDRI for lighting, etc). The blog posting calls this out because of course not everyone is already on 1.6.3 (or 1.6 at all) so it remains a relevant speed up for some users!
- Noise level now means something different than it used to mean. So rendering in two versions to "5% noise" is not a straight comparison, as 5% noise is actually cleaner now than it used to be, but may take longer to reach. An exact comparison can't be done, but in general it seems like 7% noise would be roughly the same as what 5% noise was before, so you can set a higher noise limit and reach the same visual quality (in less time).
- Pass level is also not a good comparison, as it may take just as long (or longer) to render the same number of passes, but the 1.7 result will be cleaner. So, you can set less passes now and get the same visual quality (in less time)
- For that reason, the examples posted on the blog all used a set Time to render, to visually compare just how much the noise levels were different between 1.7 and the older version. Of course for those comparisons, we leave noise visible in the image so you can visually see the difference side by side.
- The optional light solver will only give benefits with two or more lights, and will give more benefits in certain situations, as listed in the blog.
- The other reason that the optional light solver is optional is that some machines with LOTS of cores don't seem to perform well with it. I know my dual Xeon with 32 logical processors (and an older Xeon at that) shows definite improvements, but some users with newer dual Xeons with twice the cores than my set up report no benefit, or maybe even a slowdown. Still under investigation!
- Of course, we welcome feedback on any other cases and situations too!