We have one final data point we'd like to cover before bringing this article to a close. Throughout all of our benchmarking, we monitored how much power our Intel based 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 running under load. Please keep in mind that we were testing total system power consumption here at the outlet, not just the power being drawn by the processors alone.
It seems that the changes Intel made to the Presler core with this latest stepping of the chip had a significant effect on power consumption. As we mentioned earlier, this chip ran cooler and also overclocked higher than the Pentium Extreme Edition 955 we evaluated a few short months ago. And even though the Pentium Extreme Edition 965 is clocked roughly 10% higher than the 955XE, it also draws less power overall.
While idling at the Windows desktop, out test system consumed roughly 171 watts when equipped with the Pentium Extreme Edition 965XE, and with the 955XE installed it drew about 169 watts. When running the processors with a full load though, the scales actually tipped in favor of the 965XE. With 100% CPU utilization, the 965XE system drew 246 watts of power to the 955XE's 248 watts. It's not a monumental difference, but considering the 965XE is clocked much higher and overall consumes less power than the chip it replaces at the top of Intel's line-up, its clear Intel has been making progress with their 65nm manufacturing process and power saving technologies.
Of course looking at the AMD numbers, the Athlon's still have an edge in terms of power consumption, using approximately 30 - 35 watts less than Intel's flagship under-load. And had we enabled Cool'n'Quiet, the Athlons would have used less power while idling as well.