As I understood, the "App memory" is all the memory used by different applications. Now if we take a look at the list, the memory of all applications doesn't come near the memory reported:
Anyone an idea what my real consumption is and if it would be bad if I only had 16GB of RAM? I am trying to figure out whether to get a new 16GB RAM Mac oder 32GB.
Trying to make sense of those figures is like trying to knit fog.
The Mac's memory management is a) very good & b) like voodoo ;)
If you had less RAM, it would use less RAM. The more you have, the more it will use before it recycles some to be more readily available.
Having said that, we have one low RAM Mac in the building -M1 iMac with only 16GB [maximum available at the time] & it's quite easy to start to choke it if you have a couple of memory-intensive apps running. It needs more frequent reboots than all the other Macs combined [which have between 32 & 64GB.]
At the moment this is all green, which is fine. If it hits amber, we reboot it. Quitting the big users helps [usually Photoshop is top user but not running at the moment], but a reboot is a better overall refresh.
Unfortunately this only tells you “32 GB is fine. It’s more than fine”. If you asked whether to upgrade to 64 that would be easy: Absolutely no reason.
With 16GB I would expect a small amount of swapping. Before swapping macOS compresses memory which you won’t even notice; it will throw away cached files which you likely won’t notice, and swapping a few gigabytes is harmless because the SSD drive is so fast.
I would say don’t look at 16 vs 32 GB but at “what do I get for the same money”. For example if you wanted 16GB with an m3 Pro, 32 GB with the 11 cores may be cheaper and better. (It is just as fast until you really, really hammer all the CPUs. Do you do that?). Decide on the price and then get the best value possible for that money.
