Vista PCs will nod off to save power

Companies have long known the benefits of making sure their workers get a good night's sleep — and they would be wise to let their PCs do the same, Microsoft says.

With Windows Vista, Microsoft plans to put machines to sleep after an hour of inactivity. While businesses and consumers can change that setting, the software maker said they would be smart to let their computers nod off.

Microsoft estimates that allowing a PC to go to sleep during off hours, as compared with leaving it on all the time, saves anywhere from $55 (£29.55) a year to $70 (£37.60) annually, depending on the type of monitor.

"This is energy [consumed] when you are not even using the PC," said Dean DeWhitt, a director in the Windows kernel team at Microsoft. "It truly is a waste."

The company has done work in the upcoming Vista update to make sure that the PC can rest more easily. With Windows XP, programs could veto a user's request for the PC to go to sleep. In some cases, that meant laptop owners thought they had put a PC to sleep, only to discover a few hours later that the machine had remained on and their notebook's battery had been drained.

But Microsoft is hoping to make an even bigger impact with desktops. Today, many businesses leave their computers on at night. Some do it to make sure they can install security patches.

By adding the new sleep option, businesses can wake machines to install security updates, while letting them remain in the power-saving mode the rest of the time.

Also in Vista, businesses will be able to enforce the power-management settings through the group policy tool. That means companies will be able to require, say, that a screen goes blank after 15 minutes of inactivity. Although Windows XP did not have that capability built in, some third-party companies, such as Verdiem, have offered that feature as an add-on.

All that snoozing time could pay off environmentally as well. Microsoft said that by putting six PCs to sleep, rather than leaving them on, businesses can save the same amount of carbon emissions that would otherwise require an acre of trees to absorb. That calculation depends on what means are used to generate the power for the PCs, with the actual energy emissions varying greatly by region.

Tweaks still needed?
While Vista makes some notable steps forward, Bruce Twito, Veridiem's chief technical officer, said that there is plenty that has yet to be fixed in the operating system. Although Microsoft is allowing companies to set policies, Twito said that the group policy options are not flexible enough.

Twito also questions whether businesses will be able to wake machines remotely that are set to Vista's sleep mode.

"The devil is in the details there," Twito said.

Microsoft says, meanwhile, that it has made significant improvements in Vista to support waking a machine over the network.

Veridiem plans to introduce its own Vista-compatible power management software within two months of the general availability of the new operating system. Vista is slated for release to large businesses in November and to the general public in January.

Twito said it is good news to see attention brought to the power wasted by leaving PCs running 24 hours a day.

"With the attention being paid to energy waste, organisations will want to do something," he said.

Today, he said, much of the attention goes to the wrong places. Screen savers, for example, use even more power than just letting a machine idle, since the CPU and even the graphics chip are often needed.

Ever-increasing computing needs have meant that over the past 10 years, computers have been gobbling up more and more power, although recent chip advances have the potential to change this somewhat.

Vista is trying to make better use of power while the PC is on, too. In particular, the operating system now supports the same kind of power-throttling features on desktops that have been standard on laptops.

However, the fancy new Aero graphics in Vista are also fairly power-hungry. Testers of the operating system have reported significantly lower battery life while Vista than with XP running on the same machine. Microsoft has said it hopes to have nearly the same battery life with XP by the time Vista launches.

Microsoft had previously said it expected to be able to offer a significant savings in power use with Vista.

"We've done some calculations of power savings that we expect," Windows chief Jim Allchin said in an interview last year. "When 100 million machines are running Vista, the power savings around the world [will be] unbelievable."