What is cached when the Bitrix website is running?

Question

1C-Bitrix

What is RAM used for in Bitrix? We will not consider smart filter caching.
The question concerns the required amount of RAM on a physical server and how it is spent. It must be counted.
So, if in order, then this is the cache itself (we will leave its size outside the brackets, since it is individual), then, with the composite enabled, it is cached, as far as I understand, statics (index, component, that is, everything except the dynamic area), then a question that I don’t quite understand and can definitely confuse is kernel caching, this is a bitrix folder and a local folder, all this should surely fit into the RAM, but how, for example, pictures, other files are loaded if they are attached to an element, for example, and elements are definitely lot. How is it all, tell me who has real experience.
I understand what we are talking about, but since there is no real experience with this, then I can ask questions for "general development".
The question concerns only sites on Bitrix.

Answer 1

Folders are not cached. There is no reason to cache them. Script results are cached. In the case of Bitrix, these are mainly the results of component execution. Those. final html.
You will need RAM for the cache only in the case of, for example, memcached.
You can measure it like this: we launch the site on the file cache. We are waiting for the site to "overgrow" the cache. We look at the size of the cache directory, we decide on the amount of RAM.