Stand by
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Stand by is a feature of computer operating system that allows to switch computer to ACPI G1 Sleeping S3 state. Stand by term is usually used in Microsoft Windows OS and applies to all G1 Sleeping states except S4 (Hibernation). If the computer has power management support, the user can stand by the computer by going to Start -> Shutdown and then choose Stand by. When the computer stands by, the monitors and hard disks turn off and the CPU runs on low power, but the whole system is still running with the session stored to the memory. Stand by is most widely used on laptops and other portable PCs.
[edit] Standby modes
- S1: S1 is the most basic stand by mode. Only hard drives and monitors are turned off at Stand by S1.
- S3: Same as in S1, but fans and the CPU are also turned off.
- S4 (Hibernate): Another similar feature that is supported by Windows 2000, ME, XP or later is the "hibernate" feature. This feature turns off the whole computer but saves an image file on the hard disk so that the session is restored the next time the user start Windows. Note also that it takes longer time to "wake" the computer from hibernate mode, this because the computer is turned off completely as described above.
A similar feature is the ability to turn off hard disks. Windows automatically turn off hard disks if the user has turned on the feature in Control Panel -> Power Options.
The hard disks may also be turned off when Windows crashes and display a "blue screen". This goes only for Windows NT/2000/XP. In Windows 95/98, the computer is still running on full power even through the system crashes.
The stand by function is called "Suspend" in Windows 95 and "Sleep" in Windows Vista.
