As we all know, Apple has done a bunch of foot-dragging when it comes to OS X drivers for Nvidia cards. In fact, no new Nvidia cards have been added to the default OS X drivers since 10.8.5. So, starting with GTX780Ti and the Titan Black, there has been no built-in driver support.
Nvidia has been kind enough to continue supplying drivers for download and has even been pretty good about getting the updates out shortly after Apple creates a need.
While this has solved most issues, there are problems when you need to run an OS install or use a Recovery partition. Fortunately, the EFI on our cards gives you an option that unflashed cards don't have. The root of the issue is that the default OS X Nvidia drivers don't know what to do with these cards.
So, the answer is to not use those drivers and just rely on the EFI driver.
1. Boot into Single User mode by holding "S" and "Command" keys during boot.
2. You will see a black screen with a wall of text. At the text prompt, enter:
3. Hit return
4. Next type:
5. Hold "option" key to choose the partition you wish to use. On reboot the machine will be running on the EFI drivers only. You will probably notice the screen refreshing via black lines moving upwards. Moving windows, etc will be sluggish.
6. Do your install/recovery work and then restore the NVIDIA drivers to get back to work. TO CLEAR THE NVDISABLE, type:
sudo nvram boot-args="nvda_drv=1"
into terminal, this will enable the drivers and turn off the disabling. If you have other things you need in boot args (span mode for 5K, etc,) add them to that string, it overwrites existing ones.