Cool'n'Quiet 2.0 In Detail II
The CPU can now change its clock speed and core voltage without influencing either the clock speed of the northbridge or the transfer speed of the Hypertransport 3.0 protocol. AMD calls this technology Dual Dynamic Power Management .
The Processor Power Saving Indicator can inform the voltage regulation unit on the motherboard that less energy is required, allowing some of the voltage regulators to be deactivated. This increases the efficiency of the VRM unit and conserves energy. Of course, the motherboard has to support this feature.
If all four processor cores are simultaneously idle, the new C1E power state function becomes active. It deactivates the Hypertransport link, puts the system memory into a low-power state and shuts down the CPU's internal clock signal generators, leading to further power savings.
If the cores are idle when the graphics card requests data from the system memory, the Phenom can now wake the memory interface from its power-saving mode, send the requested data and go "back to sleep" without having to wake any of the cores from their idle sleep-state.
Overall, we can say that AMD has revamped Cool'n'Quiet to such a degree in version 2.0 as to make the previous version practically seem like a power hog. Since the Core 2 CPUs do not have the memory controller on-die, Intel does not have similar power-saving options at its disposal. Thus, AMD is a huge step ahead of its rival in this department.