Hello. 
I just put my gtx 780 classified acx into my case. 
I noticed that the fans are making some noise, like an loud wind tunnel sound.
Now i tried to bump up the fan speeds in afterburner and it seems that the fan noise is between 40ish to 55% speed. At 50% its very high and at 60% the fan sounds normal.
I have removed the plastic protections over the shroud and the fans so its not that.

Thanks for the link, i tried an rma instead but the new card had the same droning noise but worse and it had the rattle, gonna try rma again.