Windows 8 Power Efficiency Also Includes Apps

When you think power efficiency, you usually think hardware, but Microsoft is also working to make apps less of a battery drain.

Power efficiency is a buzzword for the hardware vendors, and Microsoft has done its part by adding different power settings to Windows over the years. With Windows 8, the company is trying to make the apps you use less of a drain on the battery.

The first and likely only public beta of Windows 8, called the "Consumer Preview," is just a few weeks from being released. If it's anything like the Windows 7 beta, expect it to be fairly solid and usable. Some pre-release builds have leaked and there are lots of details out there, if your Google-Fu is strong.

In the latest post on the official Windows 8 blog site, Sharif Farag and Ben Srour, two lead program managers on the Windows 8 team, have written about how Windows 8 will improve the energy efficiency in the OS's applications.

We expect the app to do most of its work while you are actively interacting with it. When an app is not in the foreground, we wanted to ensure that it would either suspend completely, or use limited resources based on a set of common background capabilities (like copying files), which the app can access.

Windows 8 has a new Background Tasks infrastructure that takes into account things like is Internet access needed or is the touch screen required. It also knows when a device is plugged in and will allow more apps to run when it is. If not, the apps then do nothing. Microsoft has documented this new infrastructure for all who care to read up.

Windows 8 Metro apps can also suspend apps in the background by telling the Windows scheduler not include the app in the CPU scheduling. Since the operating system is not scheduling the app, the app is not using the CPU, and it is possible for the CPU to drop into lower power states.

The great thing about this new suspended state for your apps is that they are instantly ready for you to get back to them. When you switch to a suspended app, it resumes instantaneously and takes you back to exactly where you left off. With this, you will be able to switch between more apps faster than you ever have before on Windows. 

Finally, Microsoft has also improved how Windows handles background tasks. Microsoft has created a number of scenarios based on the types of applications and what they would do in the background. For example, Windows 8 can still print documents even though the printing app may have moved to the background. If you pause a music player running in the background, the app itself is paused, not just the music stream. When a laptop goes to sleep, so are all of the apps.

It will make for interesting tests when Windows 8 ships, assuming an apples-to-apples comparison can be made.

• Windows
• Microsoft
• applications
• Microsoft
• power management
• power savings
• Windows