Optimizing the System
Before we boot the installer drive and begin installing OS X we need to make some changes to the 3D BIOS on our Gigabyte board. First, we updated the UEFI to the latest version available (F12e at the time of writing) through the Gigabyte Q-Flash utility, accessible through the UEFI.
After the new version is flashed, we need to change the Primary graphics options to force the machine to only use the installed GTX 680. If you want to use HD4000 graphics, or a combination of the two, you can find instructions on how to do it in the tonymacx86 forums.
Under the Advanced Mode version of 3D BIOS, continue to the Peripherals tab, and go down to the “Init Display First” Option. Since we will be using our GTX 680 exclusively for this build, set the Init Option to “PEG”, and the Internal Graphics field to “Disabled”
Also be sure to turn off “Wake on LAN” in the Power Management tab.
After these changes have been made, be sure to save and exit from the 3D BIOS, and shut down your computer.