Power-Up in Standby (PUIS) is a mode available on some electronic devices that allows them to boot into standby, rather than active, mode. When the user actually needs to access the device, a signal tells it to switch to active mode. This saves energy by ensuring that equipment is only fully active when it is needed, and remains in standby when it is not. Some computer systems have components automatically programmed with a power-up in standby setting, and it may also be possible to adjust equipment and accessories to enable this feature.
Historically, when power was supplied to a device like a hard drive, it would immediately spin up and go into active mode. This created a power drain, although it also made the contents instantly accessible to the user. With power-up in standby, when the power is turned on, the hard drive or other device recognizes it and starts in standby mode. It uses less power, waiting for a command from the user.
To facilitate ease of use, a quick launch feature may be built into the equipment so the user gets a near-instantaneous response when signaling equipment to wake it up. It transitions between standby and active modes, spinning up and getting ready for use. The system may be programmed to put the device back into standby when it isn’t used for a set period of time, allowing idle components to conserve energy by returning to a mode that uses less power. When the user needs to access the equipment again, it starts back up into active mode.
Not all systems support power-up in standby, which can be an important consideration when ordering a custom system or modifying an existing one. Manufacturers who produce devices capable of this feature may have documentation available to help users determine what specs their systems need to support them. It may also be necessary to go into the system programming to adjust the settings in order to activate power-up in standby mode, or to turn it off if it is not desired.
This is one among a range of options provided by computer manufacturers to reduce energy use. In addition to being more environmentally friendly, this can help systems last longer by reducing heat and not making the cooling system work as hard. Consumers who want a power-up in standby option on new computers and accessories can search for products specifically advertising this feature or ask for assistance from sales representatives.