Why does my Mac Pro boot to black screen with third-party video card when holding Option key? I have a Mac Pro 2012, and recently installed a new Gigabyte GTX 760 graphics/video card. I also have Windows 7 installed on this computer on my Bootcamp partition.

When I attempt to start up my computer and enter the "boot manager" by holding down the Option key, I get nothing. The computer chimes, but I see only a black screen, and have to hold the power button to shut off.

The normal OSX system boots fine if I don't touch anything, and I can only boot Windows if I select that partition while in OSX and restart.

I found that if I swapped back to the original video card, an ATI Radeon HD 5770, it boots to "boot manager" without a problem, and lets me select which partition on my drive to boot to.

After some research, I am gathering that this has to do with the EFI/BIOS process, but I don't really understand where that lies, nor what is going wrong.  

If I'm understanding this right, here are some questions, but let me ask the most basic and important one first:


Why does it boot to a black screen with the NVIDIA GTX card?


and kind of a tangent, and might even be answered in your answers, but:


Is there EFI/BIOS on the graphics card itself?
I don't know the precise technical reason, but unless your NVidia is specifically flashed for Mac it doesn't load the drivers until you reach the desktop. 

As you can see, this makes dealing with anything prior to that quite difficult. 

For boot camp the simplest workaround is to define the startup disk before rebooting. 

As you've noticed, keeping the old ATI for emergencies is a good idea.