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 Metro Exodus Enhanced Edition for 30 minutes.
We did notice that the 7900 XTX was a touch louder than the XT in use, hitting 41dBa on our sound meter. We saw the fans ramp up to 64%, or 1700rpm during our testing, so it's not a super quiet card but it's not raucous like a Vega reference board. There was also some coil whine from our sample, but nothing major – you can hear this in action in our video review.