"Similar to Intel's SpeedStep Technology, which originally came about to prolong the battery life for mobile users through reducing the CPU clock frequency and voltage, AMD's Athlon 64 processors support the use of Cool 'n' Quiet Technology. Advanced Micro Devices Cool 'n' Quiet Technology is targeted for both consumer and commercial use through reducing the heat output, noise level, and power consumption for systems running Athlon 64 processors. To not infer with the computing experience, Cool 'n' Quiet dynamically clocks the CPU to lower the power consumption while delivering performance-on-demand so the system will not run slow when under heavy usage (i.e. gaming, encoding, and compiling). In fact, AMD Cool 'n' Quiet Technology was recognized with Energy Star recognition in 2005 from the United States (EPA) Environmental Protection Agency. Unlike Intel's SpeedStep Technology that is limited to desktop utilization on the Pentium 600 and 800 (excluding 820) and newer series, Cool 'n' Quiet is supportive by all Athlon 64-based systems even going back to Socket 754 systems..."
