Wrong calculations or memory leak?

[Kerbal the crazyest]

Ok. I decided to watch a pc performance with KSP.

The system consumption (without apps, only task manager) is 45%. In the pc I tested (8gb ram), it's about 3600mb. 

I open KSP. It's modded. Probably many mods. Some visual enchancment (scatterer and EVE). Parts and Kerbal Konstructs. I installed community fixes so I could prevent the leaks. I load KSP and the consumption is almost full as I expected. Then I get to the home screen. At this point it's where the question comes.

At home screen, the consumption of KSP is of 2.5gb

2.5gb + 3.6gb = 6,1gb. Everything ok. That should be about 77% of 8gb. But when I check the percentage, it shows 91-94%. There's something wrong there.

Loaded KSP again, and when memory consumption was at 2,3 gb, the percentage shows 93%. And in a certain moment, when consumption was at 1,7gb, it shown 97% of RAM consumption.

With all of this, I mean: what is going on with the PC? Why is there a "ghost memory" consumption even when I installed community fixes, which is supposed to reduce the memory leaks?

This makes the game experience a bit worse. Any help would be great.