Energy Consumption: The Processor and Cool'n'Quiet Mode
Let’s start with the measurements that were taken with the processor in standby mode, with Cool’n’Quiet mode activated. In this case, the CPU switches down to the lowest possible clock rate, and depending on which CPU model is used, may also deactivate some core items and then tells the motherboard to lower the core voltage. In this case the core is lowered to 1.0 V.
In order for Cool’n’Quiet mode to work, it must be activated via the BIOS. In most cases, though, it is activated by default.
The operating system must also offer a way for the processor’s clock rate to be lowered. With Vista, in the “Control Panel”, an option called “Energy Options” is selected and changed to “Energy save mode”.
Choosing the energy saving mode lowers the CPU’s clock rate
The unburdened processor will, if the motherboard and operating system do not conflict, fall into Cool’n’Quiet mode and dynamically lower its clock rate. A Cool’n’Quiet driver is necessary for Windows XP users; it can be downloaded from AMD’s website . The latest version of the AMD driver is 1.3.2.0053.
The Phenom uses twice as much energy and comes in last place, while the new “e” models live up to their names and achieve new bests. Because the Sempron 64 processors only have one core, they trail behind the classic Athlon 64 X2 models.The combined values give the logical succession that is seen on the chart.