A computer awakening or switching may be performed if there is an activity in a network card or a modem. To make these functions operable, your devices either should be non-volatile or should not be switched off while switching to the power saving mode. You can solve this problem the standby mode, operating mode on lower frequencies or suspend mode. If you use Windows 98 or later version, you should clear the check box “Allow the computer to turn off this
device to save power”.
This check box appears on the “Power Management” tab of an appropriate device. Its setting (default value) allows an operating system turning off the selected device when switching to the power saving mode. To block the ability of device disconnection, you should clear the check box “Allow the computer to turn off this device to save power”.
To use the ability of computer awakening in case of a signal in a device, click the check box “Allow the device to restore the computer from standby mode reset by default”. For example, an incoming call sent to a modem will inform an operating system about the necessity to process this call even if a computer is in the sleep mode.
Many modern devices have the ability to awaken a system if some signal appears. But if the outdated devices are used, these check boxes may be unavailable indicating that such ability is not supported by the equipment.
To block the transition to the power saving mode, you can use the parameters that monitor the state of such devices as video card, hard disk and others. This might be necessary, for example, while displaying or printing of a large amount of data, the hard disk testing or implementing the other automatically-executing programs. Here is a list of parameters which monitor a state of devices and block the transition to the power saving mode:
The computer manufacturers often intentionally lock the possibility of computer switching by using a keyboard, although there are the appropriate parameters in BIOS. In this case, all values that you have set for switching the power are automatically applied for exiting the power saving mode.
There are also specific parameters in BIOS that enable to specify the way of exiting the power saving mode. For example, the parameter “Resume On KBS” where you can select the way of computer awakening – by pressing any button (a value “Any Key”) or by pressing a specific button (a value “Specific Key”). You can also use another parameter that enables specifying a password for
exiting the standby mode after pressing an appropriate button on a keyboard.
To exit the power saving mode by using a mouse, you may use the parameter “Mouse Power On” (PS/2 Mouse Power On, Resume On PS/2 Mouse) which may have the following values:
- Enabled – double click with the left mouse button;
- Left Button – click with the left mouse button;
- Right Button – click with the right mouse button.
As a rule, the parameter “Keyboard Power On” and similar to it has got two values: Enabled and Disabled. In order to allow for the use of a keyboard for a computer awakening, this parameter must have a value “Enabled” – this causes the unlocking of one or several parameters enabling to set the way of activation. There are also the following parameters, depending on which only separate fields will be unlocked:
A computer can exit the power saving mode by default by pressing any button on a keyboard or by moving a mouse. But is it possible to switch a computer on by using these devices?
If your computer is compliant with the ACPI standard, you can do this. Moreover, nowadays the ergonomic and multimedia keyboards have become widespread. In addition to the main
buttons, they are equipped with additional set of buttons that enable to enter a computer into the power saving mode or switch it off. Such keyboard may also have a button that enables to switch a computer on.
To switch a computer on by using a keyboard or a mouse, you may use the parameter “Keyboard Power On” (Keyboard PowerOn Function) and the parameter “Mouse Power On” (PS/2 Mouse Power On). For the correct functioning of powering functions, these both devices should be connected to a computer via PS/2 USB-port. It often happens that such function is locked at the hardware level – there may be a special jumper on a motherboard that may be called “The WakeOn Keyboard/Mouse” which is set in “Disabled’ value by default.
The opportunity of automatic computer switching is a very interesting power management feature. If your computer is equipped with TV-tuner, you have an opportunity to record TV-programs, for example football matches. But what to do if you are not at home on the match day? It is scary to leave a computer switched on alone, and it is impossible to record anything on a switched-off computer. The ACPI function comes to rescue: it allows switching on/off a computer in a set time without your participation.
Another interesting feature is to wake up after a modem (or network adapter) received a particular signal. For example, you are in an office and send a signal to your home computer, switch it on or boot it, read or record the required information and then switch it off.
To set the variable data for switching your computer on, use the parameter “Automatic Power Up” that enables to switch on a computer
daily at the same time or to switch it on a certain day and time. This parameter may have the following values: Everyday, By Date and Disabled. The wake-up parameter may be called “Resume by Alarm” that has got two values: Enabled and Disabled.
When the automatic switching of a computer is enabled, the following set of parameters that enable to set the time and date for switching is available:
- The parameter “Date of Month Alarm” (Alarm Date) enables to identify the date for switching on a computer. This parameter has got the values from 1 to 31. If the parameter is called “Alarm Date”, it has got one more value – “Every Day” that indicates the daily switching.
- The parameter “Time (hh:mm:ss)” enables to set the time for switching in the following order: hours: minutes: seconds. You may also use the following parameters to set the time: Alarm Hour, Alarm Minute and Alarm Second. The first parameter may have the values from 00 to 23, and the second and the third ones – from 00 to 59.
To switch a processor into a power saving mode, use the parameter “Slow Clock Ratio” (Manual Throttle Ratio, Throttle Duty Cycle) which allows setting the frequency of clock signal in a power saving suspend mode. This parameter may have the following values (in per cents from the normal processor frequency): 0-12,5%, 12,5-25%, 25-37,5%, … 75-87,5%. This parameter may also be called “Standby CPU Speed”. In this case it has got four preset operating modes of a processor: Max – a standard operating mode when a processor does not switch off while entering the power saving mode; High – a processor operates at one half from a
standard value of a cycle frequency; Medium – it operates at one eighth; Low – at one sixteenth.
To switch off a processor fan, use the parameter “CPUFAN Off in Suspend” which has got two values: Enabled and Disabled.
Another important parameter is “Video Off Option” (Video Off After). Using this parameter, you can define in what modes a monitor should be switched off. This parameter has got the following values: Always On – a monitor is always on even if a system is in the power saving mode; Suspend-Off – switching a monitor off after entering the suspend mode; All modes Off – switching a monitor off after entering any power saving state.
It is also possible to set the operation of a power light indicator in the power saving mode. It is located on the front of your computer. A signal from LED can be indicated by using the parameter “Sleep State LED” which has got two values: Blinking and Dual Color.
To control the transition to the power saving mode of the hard disk, use the parameter “Hard Disk Power Down Mode” (HDD Off After). Using this parameter, you can define in what state the hard disk should switch after the sleep period exceeds the given time period. This parameter may have three values: Disabled, Standby and Suspend. When selecting the value, remember that the frequent power disconnection of the hard disk causes the decreasing of its operating time. An optimal value for this parameter is “Disabled”. But if you have the comparatively new hard disk that was designed to
operate in the power saving mode, you can specify the required operating mode.
After selecting a power saving mode for the hard disk, you should specify the time period, at the end of which – in case of hibernation – the disk will enter a specified mode. To do this, use the parameter “Hard Disk Timeout” (HDD Power Down, Hard Disk Time Out (Minute)) which may have a set of values, for example from one minute (1 Minute) to one hour (1 Hour) that strictly regulate the time frames or a value “Disabled” (Off).
The values for the parameters of switching to the power saving mode of separate devices can be set automatically or reallocated manually. To define the installation methods, use the parameter “Power Management Mode” which may have the following values:
The entire system enters the power saving mode after a selectable time which can be set by the parameter “Standby Timeout” (Standby Timer Select, Standby Timers or Standby Time Out). The specific intervals of time – from several minutes (1 Minute) to several hours (1 Hour) or Disabled (Off) are used as the values for this parameter. When assigning the time interval for switching the power saving mode by a processor, remember that if you have set the time interval for an operating mode at low processor frequencies (Doze), it should be taken into account when selecting a value for the parameter “Standby Timeout”.