I found a cable thats not plugged in, I know has to do with USB has the +5v -d +d ground that was unplugged, but I checked the audio header and nothing has changed.
I also see extra cables that also arent plugged into anything, they go into the audio header come back out and end in a connector that says AC'97. The colors are : yellow blue red orange black
Probably a 1060 would be a great option or maybe a 1070 for better performance. I have a 1070 powering 2 24 in 1080p monitors at a solid 60 fps or more in all games Ive thrown at it.