There are currently no drivers available for the gtx 960M, unfortunately.gtx 960m is Nvidia, right? So you should install Nvidia drivers instead those for Intel HD 530 or I'm getting wrong?
I am having the same problem but I am not sure what to do anymore I tried what had been posted but that didn't change anything. Here is my config plist incase you might need it.
Hey, i'm following your progress with great interest.
can not get my OptiPlex 5040 to boot with video HD 530 working
7MB of vram
glitches
panic on 0x1912000, must use 0x19120006
tried DP and HDMI
would you mind sharing your config.plist since you succeeded on having the video card to fully work ?
thanks a lot