Peace of Mind

[romullus]

Don't be a party pooper Tom, if people want to have placebo - let them have it :]

Nice renders, by the way!

[TomG]

Hahahaha! I am actually sure he HAS seen a speed up, but also sure it wasn't RAM (unless it was running out) :) I will put on my party hat and join in though!

[TomG]

BTW Marcin made a good point while we were chatting - while more RAM doesn't help in and of itself, if your system was not set up with the correct number of memory sticks, then adding another might help by letting the memory switch to dual channel mode, e.g. if you had one 64 GB stick and added a second. Then it isn't the extra RAM that helps as such, it's that the memory is now configured properly for how the motherboard and CPU are intended to work. In case it helps :)

[Sebastien]

Very interesting conversation, I didn't know the RAM could slow down a render, I only thought that could limit the weight of the scene (textures, number of polygons etc).
At the office, I work with a I9 10900X, 32gb RAM and a RTX 6000. When I work on an interior scene with corona everything is fine, the IR is quite fast. But I noticed that, when I add more than 4 or 5 trees (even with the chaos scatter) everything slows down and that's a pain to work with (I barely can see what I am doing). Do you think it might be an issue with the RAM or is the 10900x too limited ?

Also, I'm waiting the release of the new 7950x to buy a new personnal computer, do you have any advices about what components should I buy ? (what kind of RAM, CPU etc)
And last but not least, I've been told that the 7950x could be, more or less, as good as a threadripper 3970x (but cheaper of course). Does the corona team have some informations about this ?
Sorry for all these questions, and thanks in advance for your answers !

[maru]

Very interesting conversation, I didn't know the RAM could slow down a render, I only thought that could limit the weight of the scene (textures, number of polygons etc).
At the office, I work with a I9 10900X, 32gb RAM and a RTX 6000. When I work on an interior scene with corona everything is fine, the IR is quite fast. But I noticed that, when I add more than 4 or 5 trees (even with the chaos scatter) everything slows down and that's a pain to work with (I barely can see what I am doing). Do you think it might be an issue with the RAM or is the 10900x too limited ?

Before we start conspiration theories about RAM speeding up rendering because of my chat with Tom, I would like to suggest a basic fact check:
If you run the Corona Benchmark (https://corona-renderer.com/benchmark) or some other CPU benchmark and the scores for your CPU are the same or close to what other users with the same hardware are getting - congratulations! There is no need to worry at all, and everything is working fine!
If you are getting a significantly lower score (e.g. 50% of the expected performance), then something is wrong, but it does not necessarily have to be RAM. You would need to troubleshoot. Forum users can help here in the Hardware section, but it's probably best to involve an "IT guy".

When rendering a simple scene (i.e. without trees or other heavy geometry with lots of materials) it is expected that both production rendering and IR will be super fast.
The more complex your scene gets (more objects, heavy geometry, more textures, complex effects like reflections, translucency, opacity on leaves, etc) - the slower your rendering will become. This is natural and expected.

If a scene slows down to "pain to work with" level after adding 4-5 trees, I would say something is wrong with the scene. Feel free to start a support ticket and include your scene. Our team will look into it: https://support.chaos.com/hc/en-us/requests/new

[Sebastien]

Thank you for your answer, I didn't mean to start any conspiration theory, I just try to gather informations and learn something new since I started using corona recently ;)

Anyway, I did run the corona benchmark of course and nothing's wrong with the CPU. I ran some tests yesterday with scattered grass and trees looking at the tasks manager. I noticed how the RAM is used as I add more and more variety of grass / trees (with their own materials), I quickly hit 80/90% of RAM used but it doesn't really affect the speed of the IR. I understood what you and Tom said, even though I think that 32gb is quite limited in my case. A few times, in other projects, Corona warned me that the computer is running low on RAM.

I work with GPU engine for a few years, Corona is a bit different so I have to adapt my workflow I guess. Even if it's a bit slower, the result is much better so it definitely worth it !