Comparison of ACPI and APM power management modes

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Comparison of ACPI and APM power management modes [Copy link]

APM 1.0 & 1.1: BIOS performs power management;
APM 1.2: The operating system defines the power management time, which is executed by the BIOS;
ACPI: The BIOS collects hardware information and defines the power management scheme, which is executed by the operating system.
APM is a software solution, so it is related to the operating system, while ACPI is an industrial standard that includes
software and hardware specifications.

3. Some common questions

1) How to determine whether the system is in S1 or S3 mode?

Answer: In ACPI's S1 sleep mode, only the CPU stops working, and other devices are still powered on. In
ACPI's S3 mode (BIOS->Power Management->Suspend to RAM is set to Enable, all devices except the memory
are in a power-off state. Therefore, the easiest way to determine whether the system is in S1 mode or S3 mode is to carefully observe
the system's situation: in S3 state, all devices stop working, and the optical drive door cannot be opened even if the eject button on the optical drive is pressed
. In S1 state, the optical drive door can be opened. In addition, in S3 mode, the system is completely silent, and all fans
are stopped. At this time, the system cannot be awakened from the keyboard. The only way to manually wake up is to press the power button on the front panel.

??2) How to cancel ACPI mode after reinstalling the Win98 system with the Setup /PJ command?

??Answer: The "PJ" parameter is not provided in the Win98 program help. This is a hidden parameter. The reason why it is
hidden is that the STR function of Win98 is not mature, and it can even be said that there are still many problems. Win98 also does not
provide the function of uninstalling ACPI. You can try to turn off the STR function in the motherboard BIOS to see if the problem can be solved.

??3) To implement the STR function, why can't the power be cut off after shutting down?

??Answer: The STR function is to save the system's operating information in the memory when shutting down. The next time you start the computer, you can directly
read the information in the memory and restore it to the state before shutting down. Its advantages are that the startup speed is very fast and the working state can
be retained . Its disadvantage is that even after shutting down, the computer power cannot be disconnected. Because the data in the memory
will be lost once the power is cut off.

??4) When shutting down Win2000, it will display "It is safe to shut down now" instead of automatically shutting down the ATX power supply. What
should I do?

??Answer: You can try the following method: Select "Settings/Control Panel/Power Options/Advanced Power Management". If
the machine supports advanced power management, select "Enable advanced power management support", and then
set PowerdownAfterShutdown to 1 in HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\WindowsNT\\CurrentVersion\\Winlogon
; if the machine does not support advanced power management, unfortunately, you can only
manually cut off the power when it displays "It is safe to shut down now?" when shutting down the system.

??5) I accidentally lost the first item "Put the computer to sleep" in the "Shut Down Windows" dialog box
. How can I restore it?

??Answer: Generally speaking, this kind of
problem . You can also delete "Advanced Power Management Support" in "Control Panel/System/Device Manager", then
restart the machine and reinstall it according to the prompts of the Win98 system.