You mean a GTX 980? That's far more than enough power, lol. I'm on a GTX 970, myself. Just open up the GeForce Experience panel and do this:
It is an integrated feature of Nvidia. There's a limited number of settings, but it records in almost completely lossless quality and barely uses any power to record. =)
EDIT: Is there any way to change the microphone to my headset? Or does it automatically do that when I plug it in?