Power Consumption and Noise
Before we bring this article to a close, we'd like to cover a few final data points. Throughout all of our benchmarking and testing, we monitored how much power our test system was consuming using a power meter and also took some notes regarding its noise output. Our goal was to give you all an idea as to how much power each configuration used and to explain how loud the configurations were under load. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the video cards alone.
The Radeon HD 3870 X2 reminds us a bit of Dr. Jekyll and Mr. Hyde when looking at its power consumption characteristics. Even though the card has a PCI Express switch, dual GPUs, and double the number of memory chips than any other card listed here, its idle power consumption wasn't all that bad. It was much higher than any of the single-GPU Radeons, but it was in-line with NVIDIA's high-end offerings. While under load though, the Radeon HD 3870 X2 used plenty of juice, and sucked down a bit more power than the GeForce 8800 GTX. Not bad actually, when you consider there are two GPUs on the 3870 X2, versus the GeForce 8800 single GPU design.
In terms of acoustics, the Radeon HD 3870 X2 also had split personalities. When first powered on, the card's fan spins up to a very high-speed and it generates a ton of noise. It quickly spins down, however, and while idling it is relatively quiet. We should also note that during normal gaming and throughout benchmarking, the Radeon HD 3870 X2's fan never spun up to its highest speed. Although the potential is there for quite a bit noise, we have to say that in practice, the Radeon HD 3870 X2 isn't much louder than any other high-end graphics card offering currently on the market.