Choose a processor with advanced power management features

Look for CPUs with advanced power management features, such as dynamic voltage and frequency scaling (DVFS), clock gating, and idle state management. These features can help dynamically adjust the CPU's performance and power consumption based on workload requirements and system conditions, leading to improved power efficiency.

The Thermal Design Power (TDP) of a CPU specifies the amount of heat it is expected to dissipate under maximum or typical load conditions. Higher temperatures impact power efficiency negatively due to increased leakage currents and resistance.  Look for CPUs with a low TDP, as these typically consume less power and generate less heat, which can help the overall power efficiency of a system. In addition, low TDP CPUs can help alleviate the need for active cooling systems and the associated power consumption.

Finally, analyze the entire system, including components such as memory, storage, and peripherals, as they can also impact the overall power consumption. Optimizing the system-level power management, including power states, sleep modes, and power management settings, can contribute to improved power efficiency.