I k ow it's a bit late but....I own a 1060 and a 4460 and the cpu is bottlenecking my gpu, definitely.
Especially if you play new titles.
In wildlands for example,no matter how much I lower the settings my cpu is around 100% and the gpu does not go up to 90%.
And like someone here said, do not underestimate how much power a 1070 offers.
After all, it's not the end of the world but I suggest if you can afford it buying another processor.