Finally, consider buying Windows hardware designed for longer battery life: Haswell machines offer a mix of low power and performance, and the "Bay Trail" Atom (Atom Z37xx series) allow everything from basic Web browsing up to moderate gaming. Displays with adaptive brightness can dial themselves down when needed. And if you're willing to fork over some additional cash, solid-state-discs (SSDs) offer faster access times and low power.
At this point, we can't say with certainty whether or not Windows or the Mac OS intrinsically offers better battery life. What we do have, however, are some possible explanations for why this is so. Microsoft's Aul suggested that if PCWorld created a so-called "Hackintosh"—a Mac cobbled together and programmed with the Mac OS, and also Windows—that that untuned configuration would favor Windows. There, the problem would be reversed: the Mac OS would be "unaware" of the hardware, and not properly tuned.
What it does suggest, however, is that it's worth buying from the PC manufacturers who are willing to take the time and effort to build a complete, holistic design. It's all well and good to cobble together a desktop machine with disparate parts. But when battery life is factored into the equation, you simply can't go too far to maximize battery life—whether you choose Apple or Windows.
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