Noise
To observe the noise levels produced by the various solutions, we put the cards in a Cooler Master RC-690 II Advanced casing and measured noise at idle and in load. We used an SSD and all the fans in the casing, including the CPU fan, were turned off for the reading. The sonometer was placed 60 cm from the closed casing and ambient noise was measured at +/- 21 dBA.
Compared to the Radeon HD 6970, the Radeon HD 7970 makes less noise at idle but slightly more in load taking it above the GeForce GTX 580. As we will see, this probably comes from the calibration of the cooling system.
Temperature
Still in the same casing, we took a temperature reading of the GPU using internal sensors:
The Radeon HD 7970 cooling system is in effect calibrated to maintain the GPU at a lower temperature than the other reference cards: 80 °C. This may be a calibration error but it may also be possible that GPUs engraved at 28 nanometres are less tolerant at high temperatures.
