We take our noise measurements with the sound meter positioned 1 foot from the graphics card. I measured the noise floor to be 32 dBA, thus anything above this level can be attributed to the graphics cards. The power supply is passive for the entire power output range we tested all graphics cards in, while all CPU and system fans were disabled. A reading under load comes from running the 3DMark Time Spy stress test for 30 minutes.
As for noise levels, the Gaming OC is another very quiet card to come from Gigabyte, registering less than 39 decibels on our sound meter when under load. This was with the fans spinning at 31%, or around 1320rpm, so by the time this is installed in a case, it would be almost impossible to actually hear the card.