HP Linux workstation x1100 Getting Started Manual page 14

NOTE
When the computer is turned off by the power button on the front panel,
the power consumption falls below 3W, but is not zero. This on/off
method extends the life of the power supply. To reach zero power
consumption in "off" mode, either unplug the power outlet or use a power
distribution unit with a switch. When the power consumption is zero for
an extended period of time, the life of the internal battery is shortened.
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