You didn't say what CPU you have, please let us know. Please also tell us how big the monitor is in pixels (not inches).
You need to tell us the LR CC version number, not that it is "up to date". The version number can be found by going to Help->System Info
Please tell us exactly what tools are slow in the develop module. Also please tell us if you are using a lot of brushing or a lot of spot healing.
CPU is Intel 6th Generation Core i7 2.5 Ghz.
GPU is 2GB Nvidia GeForce GTX 950M
Not sure about the pixel of the monitor but the resolution is 3840x2160
LR CC version 2015.7 Release
Camera Raw 9.7
I do cropping and hardly do any spot healing. As far as using adjustment brush, I would say minimal. I don't like heavy photo editing. When I use the adjustment brush, it takes like about a 2 seconds before it applies the changes. So it kinda like creating a trail behind.
Can you state the exact make and model CPU that you have?
With GPU on, the adjustment probably will be slow. With GPU off, you ought to see some improvement in brushing, but perhaps the slider tools will be slower. It's a tradeoff when you have a large monitor like yours. See GPU notes for Lightroom CC (2015)