That was always the case and has a plausible explanation (guess … as I do not know the actual source code).
When you change the size you always did / do get a panel which tells you that preparing the cache will take some time and that you have to wait.
Basically the sim does “pre-format” the cache “drive” (file). This has some major benefits:
- The file has the final size and the sim can be sure that in the future the disk space will belong to the sim.
- So the sim can never run into the problem of trying to grow the file and getting a “drive full, sorry” error.
- A “pre-formatted” (e.g. zero-filled?) file can be somewhat faster in the “access” because …
- you can ask the OS to memory map that file into your process and then you can write to it like if it were real memory
- or even if you access it as a normal file, you can seek to random positions and write data in that slot.
Now the primary question of this topic was resolved … but I still hope you find the above ideas for “why a zero fill to max size” useful.
PS: I will open another topic as I would be interested to find people who really “studied” the rolling cache. There are many things which “make no sense” to me … e.g in the Resource Monitor I can only see “read” access to the RollingCache.ccc … but never any write operations. I find that somewhat … confusing.