switchable graphics

Hi, After upgrade from Yosemite to Sierra 10.12.4 Nvidia 660M no longer works. System lost it completely. Is there some possibility to enable it back because it was faster then HD4000. Thanks in advance for your help.

Hi, It's been a long time, but I decided to resume my Hackintosh project on the dv6. I did a clean install, and I have installed Clover. Actually, everything is working brilliantly, apart from a few things: - USB 2.0 is not working for some reason... It did work out of the box, but when I...