Power Consumption and Noise
Before bringing this article to a close, we'd like to cover a few final data points--namely power consumption and noise. Throughout all of our benchmarking and testing, we monitored how much power our test system was consuming using a power meter. Our goal was to give you all an idea as to how much power each configuration used while idling and while under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the graphics cards alone.
The Radeon HD 5970's power consumption characteristics are fairly good, despite the card's ultra-high performance. In our testing, the Radeon HD 5970 pulled slightly more power than the Radeon HD 5850 CrossFire configuration under both idle and load conditions. Idle power is relatively low in light of NVIDIA's current offerings, but expectedly higher than the other Radeon HD 5800 series cards.
While we're on the subject of power, we's also like to talk about noise for a bit. Despite the Radeon HD 5970's complexity and excellent performance the card's fan spun up far less than we anticipated, which resulted in a relatively quiet experience overall. While idling the Radeon HD 5970 is, for all intents and purposes, inaudible. Under load, the card's fan is audible, but we would not consider it noisy by any means and during testing it never spun up to top speed.
We should also point out that the Radeon HD 5970 also runs relatively cool. While idling, we witnessed GPU temperatures in the mid-50'C range. While under load, that number shot up into the mid-80'C range.