i disabled boost so the standard clock rate it 1293, i also disabled throttling.
i test my card with furmark as well, my card some how throttle down in furmark but ingame it don't
here is my modded bios
GIGABYTEGTX770WindForce3XOC2GB.zip 125k .zip file
give it a shot, but remember flashing your bios it at your own risk, but if you do it right nothing should go wong