Windows Modern Standby Explained
Windows Modern Standby is a standard the enables devices to be turned off and on instantly. It improves transition between power states, giving it a smartphone like experience to Windows devices. It is a successor to Windows 8.1 Connected Standby power model. And just like a smartphone, the S0 low power idle model enables the system to stay connected to the network while on low power idle mode.
It also allows the operating system to continue performing background tasks such as Windows updates and exclusively Microsoft Store applications when the device is not being used.
In summary, the system remains in S0 (working state) while in standby, allowing th system to carry ouT background activity and also enables faster resume from a low power state, which has been slow for other power states supported by Windows.
Connected Modern Standby, which is where the device remains connected to the internet, allows for the devices to wake based on specific network patterns such as incoming emails.
Consequently, devices that support Modern Standby can stay up to date whenever a suitable network is available.
Compared to other sleep states (S1-S3), Modern Standby is significantly faster.
It is also referred to as S0 low power idle.
The requirements for Modern Standby support:
- Trusted Platform Module 2.0 (TPM)
- Passive cooling on standby
- Boot drive should not be a hard drive.
- Firmware flag for support of the standard
- Support for Secure Boot.
Systems that support Modern Standby do not support S1-S3 states.
You cannot switch between sleep states in the BIOS.
Change of sleep state requires a complete reinstall of OS.
Advantages of Modern Standby
- Provide an instant on experience. Microsoft claims that the resume time is twice as fast as from an S3 resume. This provides a mobile like experience.
- Ability to perform background tasks. Exclusively, apps from Microsoft store are allowed to carry out background tasks. When connected to internet(connected standby), the user can still be able to receive i.e. emails and calls. Also, Windows updates can carried out during this period
- Simplified wake since it is basically still in idle S0 state, it does not require interaction with the BIOS.
How Modern Standby works
The objective of modern standby is to keep the system alive to process background tasks, while ensuring that the system stays quiet enough to achieve long battery life. It is similar to S3 sleep (Suspend to RAM) but with the added benefit of allowing some software activities to run periodically. This is achieved by only waking from the lowest power state when absolutely necessary, allowing software to only execute in short, controlled bursts of activity, reducing the opportunities for software components to execute. Windows and SoC hardware also listens for interesting events such as Keyboard Events and will wake up instantly when needed. The system will wake when there is real time action required such as wake by the user and OS maintenance.
How check whether a Device supports Modern standby
- On your windows machine, open Command Promt. You can press the Windows start menu and search for it.
- Once open, enter the following command:
powercfg /a
- Check the status whether it is supported or not your device as illustrated below. Modern standby is referred to here as Standby(S0 Low Power Idle)
Modern Standby lifecycle
Wake to Modern Standby
It begins when the systems sleeps through any of the following ways:
- User pressing the power button
- Closing laptop lid
- The system idling out
- Selecting sleep from power button in Windows start menu
Apps are then prepared for transition to low power operation (windows uses API to inform Applications to prepare). Similarly, hardware components including their software device drivers, must be prepared for low-power operation.
During Modern Standby
windows transitions the system from active mode to idle mode after all software activity is stopped and the devices on the system have entered low power mode. The devices automatically transition between active and low-power modes based on software activity of the system during Modern Standby. When there are no system service or Microsoft store application background tasks that require network connection, the networking device is in the low power, protocol offload, and WoL patterns mode. When a system service or background task requires network access, windows automatically transitions to active mode. Sometimes, the system stays in active mode (with the screen is off) for a longer interval of time than normal. These longer intervals may be due to downloading critical windows updates, processing incoming emails and others. Windows components that are allowed to leave system in active state are called activators because they are registered with the power manager as capable of blocking the transition back to idle power mode. The durations of these activities vary widely but are controlled to extend battery life. Devices with modern standby can go into maintenance mode (windows and application updates, security checks, malware scans and others.) while on AC power. If a maintenance task occurs while on AC power, updates and other activities could occur and use the network if a connection is available.
It should be noted that Modern Standby has been faced with a lot of criticism from multiple users and reviewers due to massive battery drain issues, despite claims that it should drain minimum battery. However, some users have reported complete battery drain. Many have narrowed it down to windows updates which has also resulted to overheating because of lack of enough passive cooling to handle such power hungry tasks. This has also been fueled by mostly, inability to simply switch back to S3 sleep state which is not possible for Modern Standby devices.
Modern Standby to Wake
when the system resumes from standby, the display is immediately turned on and networking devices are restored to their normal, active operation modes. The time taken is normally less than a second. After display is turned on, desktop applications resume and the systems return to its normal, screen-on active working state.