GTX 780 at 15 frames per second HELP

I recently bought a GTX 780 3gb gpu from GIGABYTE (model: GV-N780OC-3GD (REV. 2.0))
and it's not working out for me, because no matter the settings and what game i try to run, it does so at 15-30frames per second. 35 at max.

I've tried installing the driver from the included disc, no luck.
I've tried installing the driver from the nVidia site, no luck
I've tried installing the driver from GIGABYTE's site, no luck.