BlameThePixel!

Some of Microsoft's most important customers aren't happy with the battery life offered by notebooks running Windows Vista.

"It's a little scary," said John Wozniak, a distinguished technologist in Hewlett-Packard's notebook engineering department, referring to the work HP needed to do on making Windows Vista more suitable for notebooks.

Vista, while touted as having improved power management capabilities that would make it easier for users to extend battery life, isn't to some living up to that promise. The main culprit appears to be the Aero Glass interface, a spiffy new user interface that makes Vista more pleasing to the eye with transparent windows and animated transitions when moving from one application to another.

When Aero is turned off, battery life is equal to or better than Windows XP systems. But with it turned on, battery life suffers compared with Windows XP.

Microsoft made some important changes in Vista that do improve some aspects of battery life, such as smarter hibernation modes that override applications that want to keep running, and simpler options for choosing a power management setting. But laptop users who spent extra money on powerful laptops to handle the graphics requirements of Vista and the Aero interface are forced to run the aesthetic equivalent of Vista Basic, the low-cost version of Vista, if they care about battery life.

HP decided it wasn't going to use the power management settings that shipped with Vista, Wozniak said. The company came up with its own set of power management settings for Vista laptops, allowing users to select different power settings, such as "power saver" or "high performance," that strike a balance between processing power and battery life. Lenovo is likewise using its own power management technologies honed over several years, said Howard Locker, director of new technology at Lenovo.

"They've really made it complex from a power management standpoint," Wozniak said. "The potential is there to do some good things, the bad thing is that it comes with the canned settings...and we didn't like any of them."

Reports that Vista was an energy hog started to surface during beta testing last year. At the time, Microsoft said many of the problems would be cleared up by the time the operating system launched. Of course, this isn't a new issue when it comes to operating system changeovers, said Richard Shim, an analyst with IDC. "When you look at a new operating system, battery life tends to be worse. When Windows XP came out, that was true, and when Windows 98 came out, that was true."

The difference this time around is that notebooks are "the growth engine for industry," Shim said. Notebook PCs now account for more than half of all retail PC sales and are projected to become the majority for the whole market by the end of the decade.

But battery life problems continue to rankle notebook users. As blogger Rob Bushway of Tablet PC site Gottabemobile.com put it, "when a consumer has to buy an extended battery to get what they use(d) to get out of a standard battery, something is really wrong."

More than one company other than HP has acknowledged the demand that Vista and the Aero interface put on a notebook PC running off its battery.

"Vista is consuming more power than Windows XP, but we have been very focused on introducing more power-efficient technologies," said Bahr Mahony, director of product marketing for Advanced Micro Devices' mobile product division.

Most attribute that power use to Aero. "In (Aero) mode, you will drain the battery faster, but you get something in return because it's cool and nice looking," Lenovo's Locker said.

The Aero interface is automatically disabled when users put their Vista notebooks into the "power-saving" profile, one of three new simplified power-management states. While that makes for an arguably duller experience, Microsoft said it commissioned a study (click here for PDF) that found no difference in "responsiveness," or application load time, between a notebook with Aero disabled versus one running the fancy graphics: implying that Aero doesn't put too much of a load on the system.

But the notebook and Tablet PC used in Principled Technologies' test had the power management setting on "high-performance" when testing Aero's performance. At that setting, the notebook won't ever compromise performance to preserve battery life, so responsiveness isn't an issue.

Microsoft isn't deterred by HP's decisions and other criticism. "We actively encourage (PC companies) to customize the default power profiles so that users get the most out of their hardware," Microsoft said in a statement.

A more definitive statement on Windows Vista and battery life should surface soon, with Intel scheduled to release new chips for notebooks next week at the launch event for the next generation of its Centrino technology. Also, Bapco, an industry benchmarking organization, is expected to soon release the MobileMark 2007 benchmark.

Microsoft, for its part, will likely have to improve Vista's battery life performance over time through the release of service packs and other tweaks, Shim said. "The (PC companies) are getting pressure from consumers--who are the notebook adopters--who are saying their number one priority on a notebook is battery life."