Noise Comparison Videos: Game Loop
Almost Real Life: Gaming on a Loop
Gaming is, by far, the most interesting usage case, since that's the most common source of graphics load most of these boards will endure. Somewhat surprisingly, all three cards behave well, even in light of the massive power consumption and heat dissipation of two Tahiti GPUs working in tandem.
EVGA's GeForce GTX 690 is still the quietest of the three contenders. Its GPUs are permitted to run warmer in the interest of minimizing fan noise, but the temperatures we measured are reasonable.
It probably would have been possible to custom-tune each Tahiti-based board to perform similarly. But, at default settings, Nvidia achieves quieter operation, while the AMD cards run cooler.