Total System Power Consumption
We have two final data points we'd like to cover before we bring this article to a close. Throughout all of our benchmarking, we monitored how much power our ATI powered test system was consuming using a power meter, and also set up a sound level meter about six inches away from the graphics cards. Our goal was to give you all an idea as to how much power each configuration used and to explain how loud the high-end configurations were under load. Please keep in mind that we were testing total system power consumption, not just the power being drawn by the video card alone.
If you saw our power consumption numbers in our CrossFire article from early last week, you'll notice that these are much lower than what was reported there. We found that our Radeon Xpress 200 motherboard was severely over-volting virtually every component, and it was having a huge impact on total power consumption. The board had our CPU running at almost 1.8v by default, which was much higher than it should have been. Once we set all of the voltages manually, power consumption shot way down.
As the graph above shows, ATI's X1000 graphics family consumes only slightly more power under full load than the older X8x0 series of cards. What more interesting to note in this case is idle power consumption. It seems the higher core clock speeds of ATI's new GPUs, coupled with the increased current leakage caused by the move to a .09 micron manufacturing process had a major impact on idle power consumption. Even the lowly 4-pipe Radeon X1300 Pro consumed more power than a Radeon X850 XT while sitting idle.
There isn't much to report with regard to each card's acoustic signature, because the sum total of our test rig's PSU and CPU cooling fans, were louder than the graphics cards. The test system's acoustic signature, from about 6 inches away with the side panel removed, hovered between 65db and 72db depending on the card installed in the system at the time. To be more specific though, we found the X1300 and X1600 to be relatively quiet, but there was a consistent, noticeable whine being emitted from their cooling fans at all times. The Radeon X1800 XL was in a similar category, but the noise coming from its fan had a much lower pitch and was easily tolerable. The Radeon X1800 XT was an altogether different animal though. When the X1800 XT's fan spins up, and runs at its maximum speed, it sounds very much like a hair-dryer on a low speed; similar to an X850. Throughout all of our testing though, our particular Radeon X1800 XTs fan never spun at its maximum speed, an only stepped up a notch or two above its slowest speed. And when running at a lower speed, the Radeon X1800 XT is very quiet, in our opinion. We've spoken with some other analysts, however, who have also been testing ATI's new cards, and they did not have the same experience as us. So, until we get to test a larger sampling of X1800s, we won't comment definitively on its acoustic output.