Power-draw, and a close look at noise
Noise
NVIDIA recommends that reviewers evaluate the noise profile of the GeForce GTX 400-series GPUs when enclosed within a well-ventilated PC engineered by responsible system integrators. The Scan system represents an ideal opportunity to investigate NVIDIA's claims.
The system is reasonably loud when idling, a situation exacerbated by having multiple fans running concurrently. The two GPUs' fans operate at between 1,500rpm and 1,900rpm with no genuine 3D load applied to them.
Firing up Call of Duty 4: Modern Warfare 2 and playing through a 10-minute stretch pushes the GPUs to the limit. Running alongside the game is an instance of GPU-Z, which logs the temperature and fan-speed of the card(s).
In spite of the directed airflow over the cards and well-balanced ventilation in the chassis, the upper GTX 480's temperature hit 94°C and fan-speed 4,000rpm within six minutes of starting the game. The lower GPU's vital stats are much the same, leading to an obtrusively loud gaming experience.
The combined noise of the non-GPU fans actually helps mask some of the aural displeasure from the twin GeForce GTX 480s, but the system is considerably louder than the HEXUS-built comparison that's powered by twin Radeon HD 5870s. Indeed, the only method of quietening down the noise profile is for Scan to invest in something like CoolIT's OMNI ALC.
