XFX Black DD Radeon 7850 975M is one of the quietest cards we’ve had in our lab - thermals are good and the card is almost inaudible all the time. Note that the card is inaudible when idle. DD cooler's superiority in cooling Black R7850 graphics card was expected since the cooler was designed to cool overclocked R7870 cards. In fact, not even further overclocking of the GPU (from 975MHz to 1050MHz) managed to change that. The highest temperature we measured after a long session of playing Crysis 2 was 73°C.
XFX fans are designed to use linear fan speed ramping controls so that fan speeds and temperatures are optimized to reduce excess noise. This helps by preventing sudden fan speed changes that tend to get loud.