3. Two Names For The Same Technology: PowerNow And Cool & Quiet

It's interesting that both the Mobile Athlon64 and the Desktop Athlon64 use exactly the same mechanism to save power or, with respect to temperatures, to ensure moderate and quiet operation. This technology is called PowerNow for the notebook processor and Cool&Quiet for the desktop PC equivalent.

The principle is simple and already proved itself in the "old" Athlon XP-M. Maximum processor performance is not constantly required for work on a PC system. It's legitimate, therefore, to reduce clock speed and supply voltage in phases of low processor loads. On the one hand, this helps save electricity and extends battery life.

Secondly, less waste heat is generated when some of the processor's resources are on the back burner, which in turn lends the notebook a less conspicuous acoustic footprint. It goes without saying that the last feature also applies to a desktop PC. If more computing power is needed, first the voltage and immediately afterwards the processor frequency are raised. If requirements recede again, both variables are reduced with a lasting effect on the processor's power consumption.

In this way, AMD's Mobile Athlon64 can apply its own rules to the CPU's in-service behavior.

Besides power scheme settings, this CPU's in-service behavior is handled entirely automatically by the operating system and BIOS without user intervention. The operating system, meanwhile, measures processor loads continuously and, via a driver, communicates with the processor to make dynamic changes to the relevant frequency and voltage settings.

In choosing a power scheme, the user indirectly determines CPU behavior