User:Willy

Just joined the mag lab. Abstract

This white paper describes how to validate and analyze the behavior of Windows 8* applications during connected standby which is one of the Microsoft* WHQL requirement for Windows 8 [1]. It explains how to identify applications that drain the battery excessively during connected standby and the steps necessary to mitigate that problem. This document is intended for software developers, Original Equipment Manufacturers, and technical consumers. Introduction

The connected standby feature enables the system to stay up-to-date and reachable whenever network connectivity is available. Much like how a phone maintains connectivity to the cellular network while the screen is off, Windows 8 applications written for connected standby are able to deliver an up-to-date experience immediately after returning from a low power state. More information on connected standby on PCs can be obtained from Microsoft [1].

When the display is turned off on connected standby capable systems, all running software (including applications and operating system software) become subject to a new set of activity restrictions. Windows Desktop Activity Moderator (DAM) suppresses legacy app execution in a manner similar to the Sleep state. It does this by suspending all applications in the user session and throttling all 3rd party services to create predictable power usage over the period of idle time. This enables systems that support connected standby to deliver minimized resource usage and long, consistent battery life while enabling Windows 8 Modern UI apps to deliver the connected experiences they promise. In addition, as hardware power states become more sensitive, software services must be well behaved at connected standby so they don’t needlessly wake/throttle the system, which would limit battery life.

The rest of this paper details tools and techniques for understanding system behavior during connected standby, and then presents two case studies of applications that can improve their behavior during connected standby. Tools

We used two easily available developer tools to understand the behavior of applications running in connected standby, as described in this section.

Windows PowerCfg