I’ve been using Corona for a while now and for some reason after doing a few test renders of a scene the GI calculation and the rendering starts to go slow, rays starts to go down really quick even tho there’s not a lot going on in the scene or froze the computer while calculating or preparing the scene to start to calculate, any one knows why? I can’t take a screenshot since PC is froze, happens n two PC’s and I’m not using a lot of geometry it’s just two low poly figures from Daz3d
Are you able to share the scene for others to test?
It’s a bit heavy cause of the textures so I’m uploading it to google drive, Btw this happens in a lot of scenes, I do test renders cause Interactive render it’s a bit slow for me but after a few test renders it does that thing where it goes really slow
Scene file with tex: https://drive.google.com/file/d/18kA1ueqIaJlw23riFi5VAt9e2NJP3qjE/view?usp=sharing
Ohhh wow SSS looks different from the ones I’ve made before, looks like a candle even tho I followed the tutorial that Coronas website has, any way to explain to me how to set up a better SSS?
If you followed the old tutorial, that means you’ve been using the volumetric method. The newer versions of Corona have a dedicated SSS mode in the volumetrics tab. You just have to chose that.
I Used the SSS Mode I even still remember settings: this is the one I followed https://corona-renderer.com/stuff/helpdesk/sss/sss-skin-mat.png and came from this page: https://coronarenderer.freshdesk.com/support/solutions/articles/12000039649-what-are-the-two-available-sss-modes-
I didn’t change any of your settings, I just hit render. 
For better SSS keep an eye on the distance scale, if your model/scene is to scale, using real world settings (distance) would be ideal.
Now I downloaded it too. SSS is scale dependent.
Yes, you really have to keep the scales either realistic or proportional to the objects. the legs are barely a cm long.
Guys Thank you, I did a fresh windows install to see if it is that, I’m gonna play with the SSS 'cause I didn’t know that I knew about volumes, if I make the figures bigger it will take a lot of RAM
Making the objects bigger doesn’t take more ram.
Not sure why but it doing it with this PC, I made them bigger and it started to slow down the viewport and I have to add grass to it
The only thing I can imagine is that it’s already slow and when scaling up, it seems to be slow.
And why do you have to add grass?
I don’t know I have 8GB of ram just like the other pc and on this one everything seems to go slow even tho is a new pc, even the video card is the same size when I play videos on youtube it starts to get slow which is weird, the grass is to give it more depth to the scene seems way too simple
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.
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
If you want to upload the new file I can have another look, your original scene rendered okay for me on my crappy PC
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.