HP Brio ba200 new power management for hp desktop pcs - Page 3

• More robust and reliable ACPI allows improved coordination between the operating system and the PC hardware, as well as centralized control by the operating system, making it more robust and reliable. These advantages are only available if you are using an ACPI-based operating system, such as Windows 98 Second Edition or Windows 2000. How Does ACPI Work? Hibernate Mode The Hibernate feature is an example of how ACPI power management is implemented in Windows 2000. The PC can be configured to go into Hibernate mode when the user presses the power button, or after a preset delay when the PC is not being used. ACPI Power Management States This table shows the ACPI power management states. You can use this as a guideline when configuring power management to achieve power saving goals. State Operating System Name Explanation S0 On The PC is in this state during normal use. All devices in the PC are usually powered on. Wakeup by Network Possible & S1 Standby S2 - The lightest sleep state. The PC hardware maintains its context. Usually, only the monitor and disks are powered off. The operating system ' goes on Standby. Similar to S1 except CPU and cache are also powered off. This state is not currently used. Not Used PC Power Use (proportional) 100% Time Required by the PC to Become Available In ACPI, called 'Suspend to RAM'. System Standby/ context is saved to main memory and is then S3 Suspend used for a fast wakeup. This Standby mode S3 is ' used instead of mode S1 on PCs that support it. All devices in the PC are powered off. PC context is saved to hard disk and is then used for a fast S4 Hibernate startup. The operating system shuts down. During wakeup from mode S4, the BIOS re- ' initializes and the operating system performs a fast startup using the disk image. S5 Shut Down In ACPI, called Soft Off. The operating system shuts down. During wakeup from S5, the BIOS re-initializes and the operating system performs a complete reboot. See "The Power Button and Unexpected Wakeup" on page 6. ' [see note*] * Remote Power On from S5 State: Current Operating Systems (up to Windows 2000, Service Pack 2) do not support RPO from S5 . However, new HP BIOSs will support RPO from S5 mode. Check the HP websites dedicated to your PC model (see page 6) for news and BIOS updates. 3