Unbalanced load sharing with parallel power supplies

An apparatus, comprising:

• one or more computer elements;
• a first and a second power supply units;
• and
• a power controller configured:
• to determine a required electrical power level for the one or more computer elements,
• to select a first value indicating a first electrical power level less than the required electrical power level,
• to convey, to the first power supply unit, the first value so that the first power supply unit delivers, to the one or more computer elements, the first electrical power level indicated by the first value,
• to select a second value indicating a second electrical power level different than the first electrical power level, the second value comprising a difference between the required electrical power level and the first electrical power level,
• to convey the second value to a second power supply unit so that upon receiving the second value, the second power supply unit delivers, to the one or more computer elements, the second electrical power level indicated by the second value, and
• prior to determining the required electrical power level, to specify an efficient electrical power range, and wherein selecting the value comprises selecting a given value so that a higher of the first and the second electrical power levels is within the efficient electrical power range.

A computer program product, the computer program product comprising:

• a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising:
• computer readable program code configured to determine, by a power controller, an electrical power level for one or more computer elements;
• computer readable program code configured to select a first value indicating a first electrical power level less than the required electrical power level;
• computer readable program code configured to convey, to a first power supply unit, the first value so that the first power supply unit delivers, to the one or more computer elements, the first electrical power level indicated by the first value;
• computer readable program code configured to select a second value indicating a second electrical power level different than the first electrical power level, the second value comprising a difference between the required electrical power level and the first electrical power level;
• computer readable program code configured to convey the second value to a second power supply unit so that upon receiving the second value, the second power supply unit delivers, to the one or more computer elements, the second electrical power level indicated by the second value;
• and
• computer readable program code configured, prior to determining the required electrical power level, to specify an efficient electrical power range, and wherein the computer readable program code is configured to select the value by selecting a given value so that a higher of the first and the second electrical power levels is within the efficient electrical power range.