We’ve featured several posts about how we’re working to improve battery life for Windows 8 PCs. In Pat Stemen’s Building a power-smart general-purpose Windows post, we discussed some of the investments that we are making in Windows 8 to enable a new smartphone-like power mode on system-on-a-chip (SOC) hardware, a mode we call Connected Standby. In Updating live tiles without draining your battery, we talked about how we’re enabling live tiles to give you fresh and current information without creating a lot of underlying activity that erodes battery life. In this post, we’ll expand on a few additional innovations that we didn’t cover previously, about how we‘ve minimized the power usage of running apps on Windows 8 PCs while still getting the most out of them.

As Pat mentioned in his post, applications can influence power consumption by consuming resources—CPU, disk, memory, and other resources—as each of those resources has a power cost associated. So the trick is to let applications utilize the resources they need while you’re actively using them, but reduce resource utilization to the bare minimum when you’re doing something else. This is true of course for the OS itself as well. Pat covered some of the work we did to improve this, but in fact, there were hundreds of small improvements made on this front—what we call “power hygiene” improvements to limit OS resource usage and activity. We were careful not to take this too far though, and undermine functionality that customers expect – like completing activities that they’ve started and then switched away from.