My system needs 2 gb of RAM when 4 gb is installed and 6,5 GB when 16 GB is installed. Any ideas? Running idle system, just everything I usually use.

Pretty much normal for Windows. If it knows that there is more ram, it will cache more to response faster. And Run better.

But on the other hand it will be the First thing that will leave the ram it some other application needs it

Most modern OS treat memory like this. Higher is better.

So, would it run slower when windows is on 64+ gb of RAM and running in "4gb ram mode"? I mean, the rest of the data is from two SSD drives...

Android does this as well, trying to use as much as possible, without using too much!

Can anyone confirm for the Darwin systems?

Unused ram is wasted ram

@620hun so... using this philosophy... do you think that google chrome ram managment is efficient?

So if ur like me u will go online and try to find a solution.... And what will happen is... The system will accomodate u wanting more ram free and start using the hard drive more... If ur not seeing a performance drop.. leave it be

@paradonym SSD's are slower than RAM so you can't expect it to be faster lol

@shelladdicted as @demiko said