We performed our power consumption measurements using an Extech Power Analyzer 380803. This device is connected before the PSU and measures the power draw of the entire system (without the monitor), including the power loss that occurs in the PSU itself. In the idle mode we start the system up and wait until it stops accessing the hard disk. Then we use LinX to load the CPU. For a more illustrative picture there are graphs that show how the computer power consumption grows up depending on the number of active execution threads in LinX (both at the default and overclocked system settings).
The power consumption of the system in idle mode is almost the same whether it is overclocked or not. In both cases the power-saving technologies lower CPU voltage and clock rate (to 1600 MHz). But we can see a difference even at low single-threaded load because the voltage and frequency begin to differ.
We can see the price we have to pay for overclocking at increased voltage: the system accelerates by less than 30% when overclocked while its power consumption grows by almost 40%.