Power Requirement Results
System Min/Max Power Requirement
It comes as no surprise that the Athlon X2 BE-2400 high-efficiency processor wins the power consumption battle, by requiring the least power in idle-after all, this is what it was designed for. All AMD64-based processor deliver virtually the same idle power, as they all switch to 1.0 GHz and reduced core voltage when Cool'n'Quiet kicks in during idle times. The maximum power requirements differ significantly, though: while the Sempron wins due to its simpler design - it has only one processing core and only 256 kB L2 cache - the 65 nm BE-2400 is clearly ahead of the 90 nm Athlon 64 X2 4600. The 100 MHz clock speed difference certainly isn't the reason for this difference.
Phenom doesn't look too good here, as it has a much higher idle power (despite Cool'n'Quiet) and a greater maximum power requirement. However, if you compare the difference between the single core Sempron and the dual core Athlons, which bring much more L2 cache, the power requirement step between dual core and quad core is less significant when looking at relative results instead of absolute values.
Avg. Power Draw During SYSmark 2007 Preview
The average power requirement during an entire SYSmark 2007 Preview run is interesting. The Athlon X2 BE-2400 is the most efficient chip for this particular workload, while Phenom clearly requires more power on average. This is due to its much higher idle and maximum power requirements.