Disabling discrete graphics (Nvidia/AMD/ATI) on Macbook Pro 2010/2011/2012/2013/2014

cross-posted from: https://lemmy.ml/post/42330116

in this inaugural post to !linux_on_mac@lemmy.ml we'll disable discrete graphics on a Macbook Pro and make the thing run exclusively off the Intel graphics.

reasons aplenty; 2010/11 models have their share of failed GPUs. those can be disabled with this trick and you get a fully functional machine that would otherwise necessitate a costly repair or it'd be thrown out, due to its age.

GPU and/or GMUX failures continued on post-2012 retina models; folks used those anemically cooled laptops for gaming, with predictable consequences.

finally, if you want to switch to linux, the discrete graphics complicates your life significantly.

this method works on all the models listed in the subject; if you know it works on other ones, please let me know and I'll add it.

the only downside, you'll lose video out as it's connected to discrete graphics.

so, boot off a macOS installer or your existing macOS partition, open the terminal and go:

nvram GfxMode=4 (prepend with sudo if it's from an interactive shell)

(todo: how to add the EFI variable from linux)

and reboot. that's it, your discrete graphics is gone. it's not present in lspci output, system report, etc. not only that, it's no longer drawing power netting you a cooler system and longer battery life.

there were earlier versions of this with some GRUB shenanigans followed by some kext/systemd magic, but thanks to the awesome folks at macrumors that's no longer needed.