Monolithic plug-in power supply

A computer system, comprising:

• one or more processors;
• a motherboard, coupled to the one or more processors, wherein the motherboard includes a first main power connector which is other than an expansion card slot;
• and
• a power supply to provide power to the motherboard, including:
• a second main power connector having a body that includes a plurality of contacts, wherein the second main power connector is mated to the first main power connector;
• and
• one or more circuit boards rigidly connected to the second main power connector, wherein a first plane including a first circuit board in the one or more circuit boards is substantially parallel to a symmetry plane of the body, rigidly connected includes mechanical connection and electrical connection, the symmetry plane including a direction of insertion of the second main power connector when mated with the first main power connector,
• wherein the one or more circuit boards include one or more switched mode power supplies to convert an input signal to one or more output signals, the one or more output signals providing power to the motherboard, and
• wherein at least one of the one or more switched mode power supplies includes a DC-to-DC converter, and
• wherein the one or more output signals include voltages in at least a subset of a predetermined set of voltages.