OS X 10.10 Yosemite - Turning off Macbook Pro's display when using an external display
Anyone figure out/know a way to turn off the display on the Macbook Pro with the lid open and external monitors plugged in? (yes, turning down the brightness (not the same as turning it off as the GPU still sends signal to the display))
This trick worked flawlessly on Mavericks:
http://gizmodo.com/5938452/a-trick-to-make-using-an-external-monitor-with-your-m acbook-way-better
tl;dr:
Here is a terminal command thats fairly simple that will allow you to keep the lid open for adequate cooling but while using the external display only. I've been using this method with my Thunderbolt display and MacBook Air since the beta of Mountain Lion came out and it works perfect. Has all the same characteristics of good old clamshell mode. Be sure to keep this written down someplace in the off chance you need to re-install, do a PRAM reset, or just want to undo it.
To execute in Terminal:
sudo nvram boot-args="iog=0x0"
To undo in Terminal:
sudo nvram -d boot-args
Once you type it into terminal I believe you need to enter your password. I then restart my machine. Now the TRICK is to either restart your machine with the lid already closed (hit restart then slam the lid!) OR turn the machine on for the first time (then quickly slam the lid!) once you are past the login screen you can open the lid.
MacBook Pro (Retina, 13-inch, Late 2013), OS X Mavericks (10.9.5)