strömsparlägen

Strömsparlägen are modes on electronic devices designed to reduce energy consumption when the device is not actively in use. They can preserve the user’s session or power down most components, depending on the level of power savings and the need for quick resumes.

The two main families are sleep/standby and hibernation/dvala. In sleep or standby, the system keeps memory energized to allow a fast resume, while most other components are turned off or reduced. In hibernation or dvala, the memory content is written to non-volatile storage and the system can be powered off or kept in a very deep low-power state, taking longer to resume but using less energy. Some devices also support deeper modes such as deep sleep or modern/connected standby, which balance low power with limited background activity.

Implementation relies on both hardware and software. Operating systems manage transitions between states, while firmware and drivers control individual components (CPU, display, storage, network). ACPI or vendor-specific interfaces define available states and their behavior. The choice of mode depends on factors such as battery level, need for data preservation, and desired speed of wake-up. For example, laptops commonly enter sleep after inactivity, while hibernation is used to conserve power without keeping RAM energized.

Advantages of strömsparlägen include extended battery life, reduced heat output, and the ability to continue working after longer periods of inactivity. Drawbacks can include slower wake times from deeper states and risks of data loss if power is interrupted during a hibernation cycle. They are prevalent in computers, mobile devices, and many Internet of Things products.