Corona A7 was faster than Corona 1

[elmes]

I've rendered scene with Corona A7 and with current Corona 1.00.01
with no changes in scene and rendering configurations.
Secondary solver was HD Cache. Settings screenshot on third attachment.

Screenshot of render end on Corona A7 after 1 hour and 45 minutes in first attachement.

Screenshot of rendering with Corona 1.00.01 in Second attachement.
I've stopped render after 1 hour and 45 minutes in second render, because it was enough to understand that Corona 1 is much slower.

Why? And is there any ways to buy Corona A7 instead of Corona 1?

[elmes]

As I remember, authors sayd that scene parsing will be faster in Corona 1. But I see in tools panel that scene parsing is also slower in Corona 1.

[PROH]

Hi. Could be numbers of reasons for this. For a start use UHD instead of HD.

[elmes]

At this time my computer renders with UHD Still frame. But as I see now in VFB this rendering will also be longer than 2 hours so again Corona A7 is faster.
And UHD will not affect scene parsing time.

[racoonart]

Moved to Bug reporting because I cannot see a reason for that in the screenshots. I'm sure it would help Ondra for debugging if you could send him the scene ;)

[elmes]

I've stopped rendering UHDCache because it is also slower than Corona A7. Here is the screenshot.

[maru]

Just a random guess because I do not remember what was the default setting in A7: maybe it's because in 1.0 "precise" and "high quality" Embree flags are checked?

[Ondra]

yes, I would need a scene to take a look.

maru: that configuration did not change since A7.

elmes: scene preparation takes the same time (only its 1+3s vs 3+1) - beware that there is new "estimated time" number in 1.0 ;)

[elmes]

This scene is too big for debugging purposes: textures 664Mb and scene with bunch of xrefs 2Gb. If it is ok for You - I will send.

but I think will be better to build simplified test scene. I will render it in one PC via Backburner, firstly with Corona A7 and then with Corona 1.00.01. If Corona A7 will stay faster, I will send you that simplified scene for further debugging.

Ondra, I didn't understand what does it mean "1+3s vs 3+1". But in screenshots
- Corona A7    -     SceneParsing/Geometry was 03:04/1:18 =total 4:22
- Corona 1 HD -     SceneParsing/Geometry was 03:45/1:00 =total 4:45
- Corona 1 UHD -   SceneParsing/Geometry was 03:53/1:13 =total 5:06
so, the Corona A7 was faster than Corona 1 from 23 to 44 seconds in parsing.

I noticed that Corona 1 brakes lights into 303 groups when Corona A7 makes only 218 light groups. Maybe this is the reason why Corona 1 is slower?
Anyway, simplified test scene will show the truth.

[Bormax]

Hello,
I have the same question about parsing time and other performance indicators. Here are two screenshots with render statistics. I didn't change anything after installing Corona 1.0, render time is the same.

[elmes]

Ok, here is the first test.

Scene parsing was 2 times faster in Corona 1 with this simplified test scene.

Very interesting that Corona 1 gave brighter result. Exposure to minus 1 equalized pictures except glass and rims.
Glass and rims materials have falloff maps (fresnel type). So 3ds max's standard fresnel falloff works differently in Corona 1.
Now these materials more realistic I think. Or maybe I have to correct material settings in Corona 1 to have same results with old Corona?
Anyway this is the reason why rendering is slower in Corona 1 but final result is more correct.

[elmes]

I found why result of Corona 1 was brighter:

Eventually solved this with the help of Mr Peter Guthrie.  The only value that corona seems to be ignoring is the 'Render Multiplier' in the VrayHDRI shader.

[elmes]

Second test is ready.

In Corona A7 I made 80 passes. Total time was 3:44.
In Corona 1 80 passes was finished in 5:04.
I found that Corona 1 made better job in same time as Corona A7 but there was only 58 passes vs A7's 80 passes.

[elmes]

Here is the GIF animation wioth difference of two same time renders.

[elmes]

Here is the settings of second test.