The reference GTX 770 and GTX 780 use the much lauded Titan cooler, which does a very good job at keeping temperatures below the 81 Celsius mark, while remaining reasonably quiet during gaming. The fan speed went fluctuated from 1140RPM at idle to 2130RPM when gaming.
It is the ideal solution for reference clocked cards and it is pretty hard to improve upon. Notice that the Gainward GTX 780 is hitting 979MHz on the core clock when gaming.
Idle GPU temperature
Load GPU temperature
Like on the reference GTX 780, the default temperature limit on the Gainward’s card is set at 80 degrees Celsius. The cooler does a pretty good job and the temperature never exceeds that threshold. After playing Crysis 3 for about 30 minutes we hit 80C and didn't manage to go over that threshold. This basically means that the card will reduce the Boost clock once it hits the threshold, staying within the thermal envelope without revving up the fan.