disable failing AMD GPU on a 2011 MBP? from Linux, because of Sierra's SIP?
There is a fix to this that allows you to bypass the discrete GPU and always use the integrated GPU! You will have to boot into archlinux to bypass SIP and disable the discrete graphics card.

Moving just the AMD Kexts will allow you to boot up the Mac, but it will be very sluggish and slow. Following this method will allow you to completely use your Mac again! I typed this response off of my 2011 15 inch MacBook Pro that recently had its GPU fail.

Here is a link to a video I made discussing it: https://www.youtube.com/watch?v=vrBLJIepJXU

Original forum: https://forums.macrumors.com/threads/force-2011-macbook-pro-8-2-with-failed-amd-gpu-to-always-use-intel-integrated-gpu-efi-variable-fix.2037591/