Controlling a power consumption of circuitry

A method comprising:

• based on an indication that processor or memory circuitry is receiving electrical power from an AC power source, selectively causing operational electrical power to be provided to a first number of a plurality of functional units of the processor or memory circuitry;
• and
• based on an indication that the processor or memory circuitry is receiving electrical power from a battery;
• selectively causing operational electrical power to be provided to a second number of the plurality of functional units of the processor or memory circuitry, the second number being less than the first number, wherein by the second number being less than the first number, one or both of a static power consumption and an infrastructural power consumption of the processor or memory circuitry is reduced when the processor or memory circuitry is receiving electrical power from the battery, and
• improving performance based on using at least part of a power saved by the one or both of the reduced static power consumption and the reduced infrastructural power consumption to provide electrical power to the second number of the plurality of functional units.

One or more non-transitory computer readable media comprising machine readable instructions which, when executed, perform a method comprising:

• based on an indication that processor or memory circuitry is receiving electrical power from an AC power source, selectively causing operational electrical power to be provided to a first number of a plurality of functional units of the processor or memory circuitry;
• and
• based on an indication that the processor or memory circuitry is receiving electrical power from a battery;
• selectively causing operational electrical power to be provided to a second number of the plurality of functional units of the processor or memory circuitry, the second number being less than the first number, wherein by the second number being less than the first number, one or both of a static power consumption and an infrastructural power consumption of the processor or memory circuitry is reduced when the processor or memory circuitry is receiving electrical power from the battery, and
• improving performance is based on using at least part of a power saved by the one or both of the reduced static power consumption and the reduced infrastructural power consumption to provide electrical power to the second number of the plurality of functional units.