Disabling your HD Graphics 4000 and using the HD 8600 series will be better for your performance.
Disabling the on-boards graphics is very easy.
My way: Boot into safe mode by pressing F8 while windows is starting up.
Type in Device Manager into the windows bar at the bottom left of the screen.
Navigate to Display adapters, there should be two options. (Intel 4000 and 8600)
Disable the Intel 4000 and reboot.
Make sure you do this in safe mode to prevent black screens and blue screen errors.
Since your computer wasn't using the HD 8600 series in the first place, it may need a driver update that can be found here:
http://support.amd.com/en-us/download/auto-detect-tool
Good luck