This mode is called ' hybrid sleep' in Microsoft Windows other than Windows XP.Ī hybrid mode is supported by some portable Apple Macintosh computers, compatible hardware running Windows Vista or newer, and Linux distributions running kernel 3.6 or newer.ĪCPI (Advanced Configuration and Power Interface) is the current standard for power management, superseding APM (Advanced Power Management) and providing the backbone for sleep and hibernation on modern computers. due to loss of power) without loss of data, because it is already effectively in a state of hibernation.

This approach combines the benefits of sleep mode and hibernation: The machine can resume instantaneously, but it can also be powered down completely (e.g. Sleep mode and hibernation can be combined: the contents of RAM are first copied to non-volatile storage like for regular hibernation, but then, instead of powering down, the computer enters sleep mode. In contrast with standby mode, hibernation mode saves the computer's state on the hard disk, which requires no power to maintain, whereas standby mode saves the computer's state in RAM, which requires a small amount of power to maintain. On switching the computer back on, the computer is restored to its state prior to hibernation, with all programs and files open, and unsaved data intact. Hibernation, also called Suspend to Disk on Linux, saves all computer operational data on the fixed disk before turning the computer off completely. In addition to a wake-up press of the power button, PCs can also respond to other wake cues, such as from keyboard, mouse, incoming telephone call on a modem, or local area network signal. A sleeping PC is on standby power, and this is covered by regulations in many countries, for example in the United States limiting such power under the One Watt Initiative, from 2010. If undesired, the behavior can be altered in the operating system settings of the computer.Ī computer must consume some energy while sleeping in order to power the RAM and to be able to respond to a wake-up event. Because of the large power saving, most laptops automatically enter this mode when the computer is running on batteries and the lid is closed. Machine state is held in RAM and, when placed in sleep mode, the computer cuts power to unneeded subsystems and places the RAM into a minimum power state, just sufficient to retain its data.

Sleep mode has gone by various names, including Stand By, Suspend and Suspend to RAM. When restored, the operation continues from the same point, having the same applications and files open. In computers, entering a sleep state is roughly equivalent to 'pausing' the state of the machine. Main article: Advanced Configuration and Power Interface

Windows 7 goes to sleep