Grappling With The Challenges Of Vista's Battery Life
However, Microsoft, Redmond, Wash., and some of its channel partners insist that Aero Glass doesn't have any significant impact on Vista notebook battery life.
"It's essentially a non-issue," said Jeff Atwood, a Point Richmond, Calif.-based Windows developer. "There's no significant hit on the battery from Aero Glass. It does do some 3-D alpha blending, but it's a misperception to say that Aero Glass strains graphics cards."
The CPU is a far greater consumer of Vista notebook battery life, and is responsible for nearly twice as much battery drain as graphics cards, Atwood said. DVD and Wi-Fi also contribute to battery life problems, he added.
Chris Flores, director of communications for the Windows Client group at Microsoft, says Microsoft's internal research into battery life in Vista shows that turning off Aero Glass will improve battery life by less than 1 percent. Microsoft also included updates and performance enhancements in Vista Service Pack 1 that can further improve battery life on some systems, Flores said.
Measuring notebook battery life is a notoriously difficult process due to the huge number of variables involved, and battery life can be inhibited by several factors, including how applications are designed, how device drivers are designed and how PCs are configured, Flores said.
"Poorly designed applications can use the CPU more than necessary and cause excessive battery drain," he explained.
Laptop displays also are major consumers of notebook battery life, and simple steps like turning down the brightness can go a long way toward conserving battery power,according to Flores.
Vista adds more sophisticated power-management tools that can be tweaked to extend battery life, including a "balanced" mode for mobile situations that require some performance, and a "power saver" mode that automatically shuts off CPU-intensive features like window transparency when running on the battery.
These are welcome additions for Microsoft partners, who say battery life is critical when it comes to making a notebook buying decision.
Dan Hogan, vice president and COO at DSR Inc., an Elkridge Md.-based solution provider that has a large education market footprint, doesn't think Vista battery issues have affected his business in any negative way.
"It makes sense that when you've got more features, you're using additional processing power," Hogan said.
Still, there's room for improvement with regard to battery life in Vista. Microsoft CEO Steve Ballmer, in a mid-April speech at the MVP Summit in Redmond, identified battery life as one aspect of Vista that could use an upgrade.
Dave Sobel, CEO of Evolve Technologies LLC, a Fairfax, Va.-based solution provider, said his engineers have complained that the power-management features in Vista aren't quite up to snuff. "They think the power controls make Vista laptops run hotter, not in terms of temperature, but in battery consumption," Sobel said.
Windows Sidebar--along with the mini-applications called Gadgets that are stored there--is one of the main factors behind Vista battery life problems, as are the search-indexing features that are built into Vista, Atwood said.
Microsoft took into account the tendency for search indexing to drain battery life, and included in Vista's power preferences the ability to suspend indexing when the notebook is relying solely on battery power, Atwood noted.
However, in Atwood's opinion, Windows Sidebar is the primary source of the battery life issues that some Vista notebook users have reported. "There is absolutely no doubt in my mind that Sidebar is the culprit here," he declared, "because CPU is far more power-hungry than GPU power time."