software does not always have the ability to see or utilize all the installed RAM. for example, I installed 48GB of 1333MHz DDR3 on a 2009 Mac Pro thinking it would up my ability in Pro Tools 8 running on macOS 10.6.8
then I find out Pro Tools 8 literally cannot utilize more than 8GB of RAM....which is what I had prior to the RAM upgrade (doh!)
I had to update Pro Tools to a newer version to have that software take advantage of the hardware I installed.
Is that graph from when the game is running or not? That graph, going by where the useage line is....the bottom being 0 and top being max of 15.9GB, it is one hash mark from the top!? That would imply 14.4GB of RAM is being used....correct?! Look at my work laptop below, see how the line is halfway up the graph, I also have 16GB installed, and the graph properly shows 8.2GB is used right now. If you're saying it never goes over 8GB, yet the graph shows it well above halfway? Doesn't make sense to me.....you say one thing but show a graph telling another story. I tend to believe the graph, no offense. And what the heck is the 87% thing on the side? If it's RAM 87% would mean more than 8GB is used