Hi,
I have a 770t-ud3p motherboard but I think the feature works pretty much the same.
The CPU Core Control Option only shows up in the bios after you have the acc set to hybrid and auto and can post with 4 cores. If you can't post with 4 cores and have your computer stable long enough to get into the bios you're pretty much screwed. You won't even be able to get to the option to
attempt to disable any of the cores.
On my rig, I can get to the bios menu to disable core 2 and/or 3 but I can't get my rig to boot the OS stably anyway.
But then again I don't have your exact motherboard and bios so I don't know for sure - that's just how it works on mine.