TechRadar takes a look at some of the changes Microsoft made in Windows 7 to offer notebook users an improved battery life. The upcoming version of Windows will better manage system resources, Microsoft will urge software and hardware makers to improve power saving features and you can also expect big savings when playing back DVDs:
Getting better battery life when you're watching a DVD is good because it means you're more likely to get to see the end of the movie. But it's also a good test of how energy efficient a PC is because it uses so many different systems like memory, graphics and IO.
Microsoft has made specific changes to Windows Media Player (and will be working with other media player software companies) like caching video in a buffer so it can spin down the DVD drive and using less CPU power to deal with DRM and copy protection.
On one notebook that added up to almost 5W less power and an hour more battery life; on other machines Microsoft is seeing at least 11 per cent improvement - that's at least 20 minutes more battery life.
Of course, software, devices and how your PC is set-up are to blame for many problems. "We see notebooks out there that we know should have four hour battery life and they only have two hours," says Pat Stemen, the senior program manager of the Windows kernel team. To fix that Microsoft is asking manufacturers to use its energy troubleshooter across the system to check settings that affect battery life. On one notebook, setting USB devices to go into selective suspend added 29 minutes of battery life.
Windows 7 systems will also check their own power efficiency every two weeks (but only if the PC is idle and plugged in); you'll get a report and Microsoft will use the anonymised information to look for devices that aren't configured for power saving and ask the manufacturers to improve them.