Corona takes a long time rendering

[Eddoron]

Ok, I assumed you needed the grass because of the rescaling.

You should check your PC, there's definitely something wrong when even YouTube videos slow it down.
My intuition says that there's something with the GPU. It's used for the viewport and also for decoding the videos on YT.
Do you use software to control clock speeds or something else concerning hardware? Wrong settings may induce such a behavior.
It's hard to pinpoint the problem, so I'd check everything, from drivers to unnecessary software, the autostart and for malware, clean up temps, etc. The whole package.

[danielmn322]

Well I did a fresh Windows install not saving files which means is clean so I left the scene and made another one completely different objects and everything, I did a few renders to check lighting and C4D had a problem and crashed I noticed in RAM the committed size increases a lot and continues to grow every time I hit render and after the crash that memory was still in the cache and pagefile like 11 gb, I was getting a really slow GI cache after the crash and rendering too I was like 15 hours with 9 hours of GI and the rest rendering time, so I figure to clean Rams cache and it started to go faster once I clicked render again, like something is wrong with the way Corona saves memory and if c4d crashes it wont clean it after making everything slow, now I had to cancel the render and re started and GI took half hour but now rendering its been for 6 hours and only making like 50 % of the first pass rendering when at the beginning I was getting pretty fast test renders of the same quality and dimensions, so Idk whats happening but it isnt the first time that happens and I start to get slow renders after knowing I wasnt

[danielmn322]

how the rendering is going

[Beanzvision]

If you want to upload the new file I can have another look, your original scene rendered okay for me on my crappy PC ;)

[romullus]

how the rendering is going

Your rays/s is extremelly low. Usually that indicates that your scene has some serious issues. There's no point to wait for 6 hours, because render won't speed up by itself unless you will fix those issues. As a rule of thumb, on a decent CPU in a normal scene, rays/s should be in a range of millions. If it falls bellow 500-800K rays/s, it is better to stop rendering and investigate a scene for problems.

[danielmn322]

Well I'm not sure what's happening, I can upload the scene in a while cause I found some kinda fix, I did a tile camera and it started to speed up a lot like each frame is now in 1 hour each and lower the resolution it was in 1500x1500 px and now 700 px, for some reason changing that help a lot

[danielmn322]

how the rendering is going

Your rays/s is extremelly low. Usually that indicates that your scene has some serious issues. There's no point to wait for 6 hours, because render won't speed up by itself unless you will fix those issues. As a rule of thumb, on a decent CPU in a normal scene, rays/s should be in a range of millions. If it falls bellow 500-800K rays/s, it is better to stop rendering and investigate a scene for problems.

See this is why I find it weird cause I always create scene test it and if lighting seems weird or an element I change it and then re render but I find it weird that after a few renders does this or when Cinema crashes like this behavior isn't new to me cause I've seen it on my old PC then that PC stopped working and I started using this one and same thing happens, I have noticed how Corona does things now the rays usually runs about 50.000 to 230.000 and once the first pass is done starts to slow down a bit but not this much, well the fix now is starting not to work I was going fast with the GI and a few min after making screenshot it started to slow down

[danielmn322]

Here's the scene: https://drive.google.com/open?id=1h5QeZXwOHtKofOwJchYHmV1KZNbuqKzD

Now I re started the render with a lower resolution and it started to work a bit normal but its not going as fast a before but at least is doing it I guess

[danielmn322]

I Created a new scene project with the same thing just copy pasted the objects and now its going fast again

[Beanzvision]

Looking at your scene again and I think you could improve a few things. Firstly your scale is very small. On the example I've attached, the square (a default cube primitive) is 2m squared, and as you can see from your scene in the circle it's extremely small. This will also affect your SSS that you have applied to your characters skin. Another thing would be to add a portal material on the outer frame of your window. This will help Corona deal with incoming light, reduce noise and subsequently reduce render times. To what point though I couldn't say. 

[danielmn322]

Ok I'm gonna try later cause rendering is now fast again so I'm gonna take advantage of it, second I don't understand how to or what to put in the portal material or what to do with it, still makes me curious about how the render does the slowing down after a few renders cause now its working again

[romullus]

Sorry, but that's not fast at all. At post stamp resolution, estimated time is more than a 5 hours, that means that 1500 x 1500 it would take a day to finish rendering. What's your CPU?

[danielmn322]

Not sure, it's been doing this, so I don't know what it is, so I made the scene bigger now I'm confused about what to do with the material portal

[Beanzvision]

Yeah I also suspect the PC might be the culprit.

[Beanzvision]

If you wish to know more about the Portal Material, please see this link. ;)
https://help.c4d.corona-renderer.com/support/solutions/articles/12000042132-how-to-use-the-portal-material-in-corona-renderer-for-cinema-4d-