Benchmarks - noise
The scale here is logarithmic, not linear, so the increase between idle and load is more pronounced than the graphs would suggest.
HD 7970 certainly isn't silent when running flat out, but neither is it annoyingly loud, given its positioning as a high-end card; we could easily game on it if enclosed in a high-quality chassis with well-directed airflow. NVIDIA's fan-control settings tend to be more conservative, enabling quieter like-for-like cards. Bear this is mind if the noise level is very important to you.
Temperature and noise are inextricably linked together. You could manually force the fan to run at slower speeds, making the card quieter, though it would be a few degrees warmer.
Overall, NVIDIA has the better reference coolers from a noise standpoint.
