RAM usage is very high

[jaguevara1011]

Specs
MOBO: b85-pro gamer
CPU: intel i5-4460 @3.2GHz
GPU: GTX 750
PSU: Cooler master MWE 600W
RAM: Corsair Vengeance 8gb DDR3 @1600Mhz

Running any game, including minecraft at lowest graphical settings, is terrible. My fps drops dramatically and at the moment, is unplayable on anything. I don't know whether it actually is my ram but everything else seems to be running fine in terms of how much is being used during game play. I bought 8gb...heard that should be plenty! Here's some screenshots of performance on several games, it usually is at 25% on idle on startup.
Idle
https://ibb.co/9WRXN7K
Minecraft
https://ibb.co/2c392sW
Gta5
https://ibb.co/HPdwQ0X
DayZ
https://ibb.co/SrHLJcF

 

[ioannis2015v]

I think that it is normal. I have 8 gb ddr3 ram and when I don't do anything (just pc open, no apps open) I have about 6,5 gb left. But when you play a game it is decreased a lot. For example when I play Pubg I have about 2 gb free ram. About the fps, are you sure your cpu is working good? Is there a bottleneck eith gpu? So I think your ram is ok, ofcourse you can upgrade to 16 which plenty.