A question about GPU usage and game optimization

Hi community

I have a question about GPU usage and game optimization.

I was just playing some BF1 before and I was wondering why if i try to play ultra settings I get 75-80% usage but sometimes drop from a constant vsysnced 60fps to like 53fps even thou their is 20% juice left and tons of CPU power and RAM left (Also connection is perfect). I currently play all high settings with ultra textures and I get around 60-75% usage constant 60fps no drops.

This weird spare usage but fps drop also happens in Far Cry 4 if I put everything ultra. I get 80-90℅ usage and drop to 50fps sometimes but if I do all high settings it sits at 70-80 constant 60fps?

I have seen this happen on some of my past GPU's as well. Is this just an optimization problem then maybe?

(Mouse over my picture for specs)

Regards