Okay, I'm a bit confused about something. The lower the speed of the cpu, the lower the power consumption, that I get. In my project on the Arduino (which has an external 16MHz clock) I use the "standby mode" of sleep, which stops most things except for the external clock.
Now, I had the clock prescaler set to as high as possible, achieving a clock speed of 62500Hz, BUT, since the standby mode does NOT disable the oscillator (which always runs @16MHz, the prescaler does nothing to affect the clock itself, right?), all I'm doing is making my software run slower. (?)
I checked the datasheet for "active supply current" of the atmega328p and the amp draw at 62500Hz would be around 0.65mA, and at 16MHz around 9.5mA. With a prescaler of 256, a piece of code takes 256 times as long to execute, thus drawing (0.65/9.5)*256 = 17.5 the amount of power as with no prescale...
So no matter what, a higher clock speed is always better for both response time of the system and power consumption..? Hm.