Energy saver: Yuvraj Agarwal demonstrates the SleepServer control software.
UC San Diego / Erik Jepsen
SleepServer creates a virtual copy of a dozing machine.
Software that lets desktop computers continue to function in sleep mode could reduce the energy consumption of office networks by around 60 percent.
Networked PCs are increasingly being left on 24/7 to allow for out-of-hours access by employees, says Yuvraj Agarwal, at the University of California, San Diego. "The administrator may want to do a backup, or the user may want to be able to connect into it," he says. But most of the time these PCs remain idle, wasting significant amounts of energy, he says.
Agarwal's solution, developed with two UCSD professors, Stefan Savage and Rajesh Gupta, is to create a stripped down, virtual copy of a machine. Software running on a remote server maintains a version of a PC's operating systems and applications. The software, called SleepServer, carries on tasks on behalf of the desktop machine while it is put into a low-energy sleep mode.
This lets SleepServer perform basic tasks on behalf of the PC, such as downloading files or staying logged into voice communications or instant-messaging software. When more complex activity is required, the software wakes up the computer, says Agarwal, a process that typically takes less than 10 seconds.
"Normally if I put my computer to sleep, then Skype is going to show that I'm offline, or I won't be able to continue downloading a large file from the Internet," says Agarwal. SleepServer maintains a fast connection, over the internal network, to each desktop, so any files it has downloaded on behalf of a PC can be transferred quickly.
The energy savings come from the fact that each server can host up to 500 virtual machines. Even the latest low-power computers consume around 45 watts of power when idle. In contrast, a single SleepServer machine runs at just 300 watts, Agarwal says. Using fully functional virtual machines and low power "thin client" desktop machines could reduce power consumption further still.
In trials, details of which were presented at the USENIX Annual Technical Conference in Boston last week, 30 PCs used SleepServer for two weeks. The energy they consumed was dropped by between 27 and 86 percent--an average reduction of 60 percent, says Agarwal. With up to 80 percent of electricity consumption in modern offices coming from computing equipment, the savings a SleepServer offers could be roughly equivalent to $60 per computer each year, he says. Fifty PCs in the computer science building of UCSD are now running SleepServer.
Other software can be used to wake up sleeping computers, such as Apple's Wake-on Demand and Microsoft's Sleep Proxy. But these applications do not carry out tasks on behalf of a sleeping machine.
"It's a clever approach," says Howard Noble, principle investigator of the Low Carbon Information and Communication Technology Project, at the University of Oxford, in the U.K of SleepServer. But Noble says it would be preferable to be able to power down computers completely. Modern computers can still consume as much as five watts when asleep.
Agarwal says this isn't an option in most cases. "If you turn [a machine] off completely it is extremely cumbersome and slow to turn it back on," he says. Also, this means users have to reopen or log back in to applications, he says.
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Be funny if we could put people in cold-sleep or hiberation and take over neccessary brain functions remotely at 500:1. More seriously, cloud computing and this sort of backup support could monitor houses or factories or machines, waking them up, so to speak, when something truly interesting happens.
The enemy of the good solution is the perfect solution.
Your sentiments are a good way to ensure some really good improvements in idle computer efficiency occur in many years rather than this year.
Going from a minimum of 45 watts to 5 watts is an 88% improvement, while eliminating most of the drawbacks to current methods of reducing idle computer energy use. And I know of no good evidence that a significant number of computers come out of standby too early. Usually they don't make it into standby in the first place, because users don't know how to set it up, or the energy savings isn't a priority to them.
If SleepServer has a solid client to control the host PC that returns it to standby as fast as possible after required power ons, and businesses implement this functionality with reasonable quality assurance, then SleepServer can improve the situation for the widest number of use cases more than any technology on the near horizon.
Its good don't get me wrong. But this idea is better...
Each computer has an off switch that can be remotely turned on and off.
Oh wait for it....machines can have this functionality already..its just cost.
To simplify it further for businesses lets have power boxes wired to a remote console that can control the power.
Ie extension cords and sockets are all fitted with a wi-fi attachment that controls the power that turns on all machines when the power comes on automatically. The attachment could be a simple plug-in like adapter extension.
Okay so i have just invented another new technology that actually will work better...whoopy do. I still dont have the money to build one or show you one working....
Just get everyone to turn off their machines when they leave...wow now thats energy saving and if the IT dept needs a machine or machines on... they just flip the remote switch, perform the action and return the machines to off or if they forget they go back to sleep.
I'm not particularly sure what this approach does that Wake On LAN (WOL), which now even works over wireless, can't do. You'd be moving a lot of data in most cases, when simply being able to suspend (or hibernate) and resume on-demand will suffice, and will have far less moving parts than the proposed solution would entail.
Yes i agree,
As they stated there whole system is there to make sure people appear online in messenger...when they arent there...
Clearly we never imagined such a demand like this was so sort after...
I disagree... Wake-on-LAN has not found traction within enterprises because its mostly hard to use and requires lots of configurations to actually work. Issue is that even if you do get it to work people don't want to do the extra steps required to sending a WoL (magic) packet. I am even further unsure about Wake-on-Wireless LAN -- last count I looked only a few Intel cards supported it and it was still very touch and go. For example even then it did not work if you had any encryption (WPA2 or 802.1x) in use which is pretty common now.
I think this technology can be pretty useful for saving energy in PCs... After skimming through the mentioned paper it doesn't look like there is any data transfer needed if you just want the PC to wake up (e.g. on an SSH connection )...Additionally, it looks like they can support things like waking up on a VoIP call, doing file downloads in the background which I can imagine are potentially useful for people...
I think cloud applications are a better solution. Power of the work system and log-in to the online account remotely.
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Energy Dashboard at UC San Diego
The plan is to fully integrate SleepServer with Energy Dashboard, which is a UC San Diego energy-management system with a Web interface that will allow individuals on campus to monitor their own energy as well as the energy use of the campus.
http://cse-ece-ucsd.blogspot.com/2010/03/sleep-talking-all-over-campus-energy.html
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