Note: RC stands for “Release Candidate”
Taken from page 3 of Anandtech.com’s article, “Windows 7 Performance Guide”:
Finally, battery life, one of the sore spots with the RC, has finally gotten the kick in the pants we were expecting to see. We’ll get deeper in to this later when we look at benchmarks, but for the time being we’ll note that while the RC offered a battery life similar to Vista, the release version of Windows 7 offers battery life well ahead of Vista in all cases, and depending on the exact hardware used similar to if not better than battery life as compared to XP. It looks like Microsoft and driver authors have finally come through on significantly improving Vista’s lackluster mobile performance.
Yes, yes! Not that I’m planning on getting a Windows 7 equipped laptop or desktop anytime soon, but one thing that irked me from benchmarks was seeing that battery life under Windows 7 looked pretty much the same as Vista. Which, in most cases, was significantly lower than XP and Mac OS X. And this was in the Release Candidate (RC) version of Windows 7, which was supposed to be pretty much… a “finished” version of Windows 7. So I’m glad to see that they’ve made such a fundamental improvement since the RC. Anyways, the above excerpt was taken out of page 3 in the 18 page article, so I’m going to have to read on to see how big of an improvement over Vista they’ve made (in terms of battery life).
UPDATE: Well, I finally got to the battery benchmarks and they referred to an older article (benchmarking the RTM or Release to Manufacturing version) that I remember reading before, which when I read it at the time, I didn’t think showed much of an improvement over Vista. I guess things must have been really bad a couple of months before that when the RC was released.