Benefits of new hardware

I just got a 1080 GTX and I have it running on a very old I7 930 with PCIE 2 with 16GB DDR3 and it’s running much better than my old 960 with 2GB. I don’t game at all, I would be using it for blender and some Photoshop. I have never had any issues with Photoshop running slow, I am only looking to improve particles in the viewport, render times and viewport live render. Considering that most of the work is done by the GPU, would I benefit significantly if I got a new CPU with a MOBO with PCIE 3? I was thinking of getting a I7 6800k and 32GB of DDR4. Is it overkill or should I just get a lower end CPU and a MOBO with PCIE 3?