Question about Gigabyte GTX 970 Windforce 3X

Because the components that get hot are so small, they cool down very quickly due to the arrangement of the components, which is normal. However, I find it strange that it gets so hot! Mine has the stock cooler, is overclocked to the limit (+150Mhz GPU, +600Mhz memory, voltage +50mV) and for me the card gets a maximum of 73°C after an hour of benchmarking. The fan still runs at a comfortable 2400 rpm. During games, it sometimes spins up for half a minute but then slows down again. I have to say the card is a monster for the price! I would look into the problem :)

The funny thing is that the temperature is back at about 50c after 7-10s?