In test driving the Windows 8 Consumer Preview, I set-up the development environment today with Visual Studio 11 Beta and began to read through some of the SDK materials. Since my computing is primarily done on laptops for mobility reasons and the fact that nowadays some laptops are desktop equivalents; I usually toggle the power settings between “Power Saver” when I am casually computing, and “High Performance” when I am developing applications. This means that I don’t want the system to perform any power saving actions such as dimming the display or turning off the hard drive because, well, it’s time to be productive.
Well, today I discovered that the default behavior of the “High Performance” setting is configured differently in Windows 8 than in Windows 7. More specifically, the “Adaptive Brightness” setting, when set to “On”, continues to dim the display. Yes, I know, and you are correct, this is how it should behave. However, in Windows 7, choosing the same power setting does not continue to dim the display.
The solution, of course, was to open the “Advanced Power Settings" dialog and set the Adaptive Display setting to “Off” as shown in the images below; and when you have saved the settings, this selection should remain when you toggle between power plans again in the future.
While this was a trivial matter, I found it interesting that the exact same settings in Windows 7 cause different behavior. This leads me to speculate that the power plans in Windows 8 have been optimized for tablet use. This actually makes sense given that the display is one of the top components that consumes much of the battery life in mobile devices.
In any case, if you find yourself wondering why your Windows 8 device continues to dim the display while you’re reading, disable the adaptive brightness setting.