Yeah do not worry about fan speed.
I have mine overclocked to 880 core, 1050 memory, 1760 shader from stock 725/900/1450. It underclocks to 50/68/101 at idle so the temp is ~27*C.
At full load in games I'm yet to exceed 58*C after many hours. I get up to around 70*C in Furmark.
Make sure to download driver version 266.58 from the nVidia website.