That's the 0 dB mode - fans don't turn on til 60C.
 
If you absolutely can't stand that (it is perfectly safe, BTW), you can set a custom fan profile in PX1 or Afterburner.
 
FTW3 models have a dual VBIOS, where the OC VBIOS runs at a minimum of 33% - but the XC variants only have a single VBIOS and only the 0 dB mode.