In my last post, I introduced you to InstantGo
(previous to Windows 8.1, we called this Connected Standby), a new power model used on some Windows 8.x systems. InstantGo is a tight integration of software (firmware, drivers, OS) with System on Chip (“SoC”) hardware to provide a sleep mode with long battery life and a connected, instant-on user experience.
In this post, I’d like to introduce you to Sleep Study, a new tool available on Windows 8.x systems with InstantGo that can help you identify sources of battery drain that occurred while the PC was in sleep mode (that is, when the screen was off).
Sleep Study tells you how well the system slept and how much activity it experienced during that time. While in the sleep state, the system is still doing some work, albeit at a lower frequency. Because the resulting battery drain is not easily perceptible (you can’t see it draining), we built the Sleep Study tool in Windows 8.1 to allow you to track what is happening. We thought of simply using traditional logging to do this, but ironically, the logging itself would drain the battery. With this in mind, we designed the Sleep Study tool to minimize its own impact on battery life, while tracking the battery draining activities.