Bottleneck?

Is my H170-HD3P Gigabyte board, with an i5-6500, 16 GB of 2400mhz DDR4 ram, bottlenecking my Strix 1070 ti?

I can play everything max graphics settings but when there is a lot going on (max supply in SC2, heavily populated areas in Witcher 3); I notice frame rate drops. To me that says my processor is lacking since it happens when there are lots of things being processed on screen.

Am I correct?