Power Consumption & Temperatures
Power consumption levels of the Radeon HD 6990 are considerably better than a pair of HD 6970 Crossfire cards, using 15% less power under stress conditions. When compared to a single GeForce GTX 580 graphics card, the Radeon HD 6990 used 18% more power to deliver on average 48% better performance.
Thermals were also kept in check, however the Radeon HD 6990 is easily the loudest graphics card we tested. You could say AMD's efforts to keep the card running cool were successful, but they completely forgot the "quiet" part of the equation. Still with a maximum temperature of 88 degrees we were surprised, even with the noise.