The hardware that makes up today’s laptops has gotten quite efficient and we have worked hard to improve Windows' ability to manage that hardware. One of the biggest improvements in the mobile PC experience for Windows since the early 1990 is longer battery life. The trick here is to make the system as efficient as possible while still maintaining a great user experience. At the same time, the increased cost of electricity has become a key factor for enterprise customers who are under continued pressure to manage TCO (total cost of ownership). As a result of all of these factors, we decided to make some extensive changes in the power management sub-system for Windows Vista.
The Windows Vista power management goals were simple: 1) making turning a computer "off"/"on" as reliable, simple, and fast as turning off/on a TV, and 2) maximizing the active usage if on battery and reducing the energy consumption if on A/C power. The first goal involved not only improving the predictability of the behavior when a PC was switched "off", but more importantly changing the model for what "off" and "on" means. Everyone knows that turning a TV off doesn’t really turn it off. It is still available to receive the remote control signal, etc. so that it can come back on quickly. We wanted to emulate this for Windows Vista machines.
To the degree possible, "off" equals "sleep" in Windows Vista, where the system state is saved in RAM. This creates the best balance of user experience for speed of resuming and lowest usage of power. However, if the PC is running on batteries even that minimal power usage could drain the batteries eventually. Remember the top goal here is to make sure that we can enable a fast on experience (like your cell phone) and a fast off experience, while still making sure that you don't lose your work when a Windows PC is turned off. To do this, we created a new approach that we call "hybrid sleep state" that is the best of the sleep and hibernate modes (which existed separately in Windows XP). In this hybrid mode, the state is stored both in RAM and on disk, so nothing can be lost if power goes out. Then the system is suspended into the low powered sleep state for a period of time (like your cell phone). Normally, when the user returns and wakes the machine, system state is just restored from RAM, and resume responsiveness to the user is fast. However, if for some reason power is lost (for example, if the PC is unplugged to move it -- like you might move your TV), the system can still resume from the hibernate image previously saved to disk with all context and data intact.
While Hybrid Sleep can be used on a laptop computer, it isn’t as applicable to laptops for a couple of reasons. First, a desktop is vulnerable to power loss, while a laptop can of course run on its internal battery. A laptop can also detect or even wake up from standby when the battery is low so Windows can save everything to the disk before the battery is completely drained -- and remember, in the sleep state all the battery needs to do is to refresh the RAM, which takes very little power. Also, mobile users want a grab-n-go usage model, so taking extra time after the laptop lid is closed spinning the disk to write out a potentially large hibernate file could be a problem. Lastly, after a laptop has been in sleep for a while, the system will wake up and immediately go into the hibernate state. This state uses absolutely no power, so even the minimal battery drain used in standby is removed. If the system is in this power state when the user wants to use the system, then the system state is restored from disk.
In either case (suspend to RAM or disk), though, the user conceptually just thinks of "on"/"off." In the case that the machine hasn't been used for a long time, then the only difference to the user is that it just takes slightly longer to resume back to where they were. As I mentioned, if the system is A/C-powered, then by default we leave the system in the sleep state (never going into hibernate) so that the machine can be virtually instantly available, but still have substantial power savings compared to past systems. The bottom line is that because there is no reboot, the PC can respond much more quickly.
In order to ensure that "off" worked effectively with this new model, we needed to address some unpredictability that occurred with sleep in Windows XP. Instead of waiting for each application, service and device to agree before going into power saving mode, in Windows Vista we changed the approach so that we give the application, services and devices a notice of the impending suspend and then wait a maximum of 2 seconds for them to finish up any work and put themselves into a state they can continue from when the system wakes up. With Windows Vista there won’t be any more sinking feelings when the airplane is at 10,000 feet and you reached into your laptop bag to find the laptop all cozy and warm because it didn’t go into power saving mode when you were running for the plane -- caused because some device, service, or application wasn't well behaved. One of the interesting things about the new power management system is that Windows Vista is able to come back from the sleep state so quickly that the first time you open the lid on a suspended Windows Vista laptop you might wonder if it was on the whole time -- trust, me it wasn’t.
Our second goal was to reduce the power consumption of PCs when they are idle. In the past the few users who did shut down their PCs when not in use had to sit through a long boot process to get their PC back on. However, many enterprises and home users just leave their PCs on 7x24. While this is nice to be able to have the PC ready to respond when you sit down at it, powering a PC overnight just so it can be available to you when you sit down at 8AM is a pretty expensive approach.
In order to achieve the second objective -- reducing power usage -- we made changes to dramatically improve idle power consumption. The dream was to reduce power consumption by powering key components down more frequently and leaving them powered down for longer periods while still maintaining a great user experience. For example, while Windows XP did a great job of lowering CPU speed and voltage whenever possible, in Windows Vista we added enhanced capabilities to use power more efficiently on multi-core systems. And we have created new APIs so that driver and application developers can get notifications about the power scheme being used on the system and then adapt their behavior for the power scheme. Finally, all of the power management configurations parameters can be controlled by the IT department (on a PC-by-PC basis) using Group Policy if they want to tweak the defaults, making corporate deployment of these features easily manageable.
How much power is used and how great the experience is depends on all the equipment and software attached to your system. So, we created some great tools including the Power Event Monitoring tool to help develop and test applications, as well as some great content for developers on power management. We have also made the power management system extensible, so that instead of writing separate power management solutions, third parties including computer manufacturers can closely integrate their unique features and capabilities with Windows.
If you look at the impact in power-savings terms of the Windows Vista design, it is pretty amazing. (BTW, there is a great white paper on this on Microsoft.com, but I will net it out for you here). A typical Pentium 4 PC with a 17" LCD monitor draws about 102.6 watts of power (think about a 100 watt light bulb). That same PC and display in a sleep state draws only 5.6 watts, or 97 fewer watts. If you figure that a PC is used for active work for 10 hours a day, 5 days a week, 52 weeks per year, that is 2,600 operating hours. With 8,760 hours in a year (365*24), there are actually 6,160 potential idle hours per year. Since sleep mode uses 97 fewer watts than full power mode, the total savings is 597 kWh per year -- and by the way, the impact is obviously even greater (760 kWh) if you use a CRT monitor since they draw more power than LCDs.
The paper uses an estimate of $0.0931 per kWh from the US Department of Energy, so for a home user with one PC, the savings amounts to $55.63/year (more if the PC is used less than 10 hours a day). While that is great saving for a home user, think about an enterprise with 10,000 desktops where the potential cost savings would be $556,300/year -- and we haven’t even tried to estimate the HVAC savings. With IT budgets becoming sequentially tighter year over year, it's nice to be able to have this kind of impact.
I strongly encourage you to use the defaults in Windows Vista. And no need to think much anymore about different power-saving modes and terms like hibernate, sleep, etc -- just hit the symbol for "on" and "off" and let the system do the thinking and power saving for you.
well jimall you have shared a very vital info with us! i appreciate it.
Is this related to the hard disk parking its head after 6 seconds of idling? It makes a clicking noise quite annoying. As there are many 6-second periods of time idling during normal use, it sometimes clicks 2 or 3 times per minute. Is this normal?
Thanks in advance for your answers.
Saving energy is great and all, but as for me, this feature kills me, for me, I want my computer to turn off the screen, but it's actualy 'on'. Because once I set for my screen to turn 'off' at a set amount of time, it cuts off connection to the internet, meaning the system is suspended until the mouse is moved. Right now, I need something which turns off the screen making it dark, yet does not terminate internet connection, this goes 'closing lid' as well.
What I really want is a feature where I can control what 'on' and 'off' does.
I recently went to Vista on my laptop, and have constantly had a "plugged in, not charging" notification for my battery state.
Is there a white paper/faq/blog some where which stipulates the triggers for Vista to charge a laptop battery? Even with a completely drained battery, the battery does not charge.
Vista has a nice feature called "Help and Support" that you can access from the start menu. I typed my query: power off button
The FIRST result said the following:
Change the function of the Power button on a mobile PC
By default, pressing the power button on a mobile PC turns it off. Alternately, you can choose to put your mobile PC to sleep or put it into hibernation when you press the power button. You can apply the same setting to all of your power plans or you can apply different settings to individual plans.
To apply the same setting to all plans
Click to open Power Options.
On the Select a power plan page, click Choose what the power button does.
On the Define power buttons and turn on password protection page, next to When I press the power button, choose what you want your mobile PC to do when you press the power button, both for when your mobile PC is running on battery and when it is plugged in.
Click Save changes.
To apply a setting to a specific plan
On the Select a power plan page, click Change plan settings for the plan that you want to change.
On the Change settings for the plan page, click Change advanced power settings.
On the Advanced settings tab, expand Power buttons and lid, expand Power button action, and then choose what you want your mobile PC to do when you press the power button, both for when your mobile PC is running on battery and when it is plugged in.
Change what happens when you close your mobile PC lid
When my computer wakes, do not require a password to unlock it
Change, create, or delete a power plan (scheme)
Power plans: frequently asked questions
How can it get any better? The very first result in Help told me how to solve your "problem" with the power button. The defaults can't make EVERYONE happy, but if you spend 20 seconds in the Help feature the answer is clear. The power plans are fully customizable.
(There's a common saying regarding reading the manual that I'll refrain from posting here.)
my name says it all, shame i had to get my new laptop with vista on it, how do i downgrade to xp
main point, when i switch off my laptop , i want it to be off how do i do this, i do not want it to sleep or to hibernate
will ahve to find a forum that explains how i can extend my screen from xp laptop to vista laptop, and no , i dont want to do it vice versa for several reasons
I have Vista on the new Dell XPS M1330 and one thing I dislike about Vista is how the Power Management handles this situation. I have my power settings set to stay on when I close the lid and the power cord is plugged in and to Sleep when I close the lid and it is running on the battery. So sometimes when I am getting ready to head off to class and I have my laptop on my desk plugged in and turned on, then I close the lid, so it stays on, then I unplug the laptop. Now here's what happens I put the laptop in my bag thinking it is "sleep." However when I get to class I open the lid and the laptop is HOT! and its still on, because it isn't programmed to switch to the selected behavior of closed lid-on battery when the lid is already closed. I wish MS would really fix this. I just don't think about doing this in any particular order especially when I am in a big hurry.
I need to buy a Vista.
hgld: out of curiosity, have you tried the recently released patches that address power management issues?
Check out: http://support.microsoft.com/kb/941649
Vista power management is the biggest joke I've seen. I'd like to see an update to this post as clearly there are problems and it frustrates me to see that they aren't acknowledged.
I completely agree with richiec's comment. Macbooks can last for weeks in sleep.
I have a brand new Sony Vaio G-11 which is supposed to last for 9 hours - but this is undermined by Vista's poor power management. It can't even last a day in sleep.
Microsoft - How are you going to fix?
This guy has the same problem as I do with Vista
When I use this option, my network connection (that is to my ADSL router) is off and I have to re-initiate it (when it wants to, sometimes it takes a re-start). I would love to use this feature, but not at that cost, tried it in several machines at the office, still the same results with a normal Belkin router :-(
issues i have with the power management:
- options for pressing power button now disclude 'ask me what to do' (are you serious?)
- screen saver works only when it wants to, apparently
- with an external display attached, it is impossible to close laptop and have it truly 'do nothing' (it swaps entire desktop to ext display screwing up my multiple monitor desktop)
i'm glad i still haven't activated. XP is much more productive and there isn't anything i need to get done that can't be done there. i'll check back in a few months. till then the power screw ups alone are more than i needed to revert. now i just need to remember to image the install after i've suckled all my updates during that small glimmering point in time between patched and infested with bloatware. bah, what is the computer world coming to? sorry guys, Vista just isn't ready to actually be used by anyone but a fanboy yet. i need to get actual work done.
please, please, please go back to the drawing board and fix vista's power management. I am on a brand new HP laptop. I have fully charged my battery and put it in standby only to have my battery drained within hours. My Macbook can last weeks. I am not the only laptop user going through these issues.
ditto the remarks by Cmdrdata;
imagine this scenario:
High performance chosen on
notebook running Vista Ultimate, with batteries removed;
customized plan to dim display after 1min; then disabled all settings for turning off hard disks/hybrid sleep.
Notebook will randomly "freeze" after an extended period of time.
2. Changing to customized plan/setting is difficult; basically only the 3 built-in schemes are easily selectable;
so if I wanted to switch between Never Turn off the Display, to Turn Off after 1min ->
I'd have :
1. left click More Power Options on the icon,
2. left click Plugged In/OnBattery, then type either 1 repeatedly or N.
3. then click Save Changes.
previously -> you can just click on the power icon and select your customized scheme.
Pray tell - how is the UI improved?
I am all for easy power management and reduction of power consumption. What I see missing in VISTA that has us considering turning OFF the power saving features is that when a user has network applications open and connected the system will still go into sleep mode.
Even at the simplest of levels, we would like to be able to have power management enabled when a user is logged off the system but while they are logged in to operate differently.
Even Outlook connected to Exchange server results in authentication issues sometimes after a sleep mode resume. It comes up and asks the user to re-enter their password so it ca reconnect to Exchange. It also offers to the user a check box to save this password locally. The latter is not something you want happening in a secure network environment.
Any help of guideance would greatly be appreciated with respect to Database Applications that are connected at the time a device goes into sleep mode.
Can some one please explain excactly how the hibernate feature works and why it is so fast in rebooting the computer compared to a cold start?
As a new Windows Vista user I am very disappointed in power management support. I own an Acer Travelmate 4002 WLMi notebook, which has a very good configuration (Pentium M 1,6 GHz, 2GB RAM, Radeon 9700 with 64MB of dedicated RAM, 80GB HDD) and has passed all test in the Vista upgrade adviser prior to install. The BIG problem is that there is no driver for the notebook battery and Vista does not accept the system as being battery enabled. NO WINDOWS MOBILITY CENTER SUPPORT! I have contacted Acer Customer Support in Hungary and in Germany, but despite the fact that the problem has been announced when RC1 was made available there is no solution to the day. Microsoft also knows about this issue, since on their Technet forum there's a discussion with Missing drivers for "Microsoft SMART Battery Subsystem" title. Several other Acer models are affected along with Benq, Toshiba and Packard Bell systems. If somebody reads this besides me PLEASE write some drivers and put them out on Windows Update because MS is loosing customers because of compatibility issues.
have a nice day!
PS: if MS is still offering free Vista licences to people who report bugs I certainly deserve one.
contact me: email@example.com
"poweroffplease", You can change the power buttons settings in Vista by going in to the Control Panel and into the power settings applet and selecting advanced. There, you will see options for both the Start Menu power button default and the system case power button and you can change them both over to Shutdown instead of sleep or hybernate. You can even disable the Hybrid sleep state from in there!
Hope that helps!
I can't find a solution for this anywhere, but it does appear that lots of other people are having it. When I boot or resume my laptop, the power manager somehow tricks itself into thinking the machine is "plugged in, not charging" when in reality, it is NOT plugged in and running off the battery. The huge problem with this is that wrong power scheme settings are used, and the machine will shut off without warning when the battery is drained. The only way to get the power manager straightened out is to attach and disconnect the power supply. That's weak.
This is all a bad joke. All I want to do is have the machine do is power OFF by itself after a period of inactivity. Hibernate is not an option (32GB of RAM) and sleep does not shut down all the drives or idle the CPU (yes, speedstep is installed). Do you know how hot a dual quad core XEON gets? I travel and all I want is to do a WOL and let it shutdown again. If I do an intentional power off, my understanding is that WOL will not work? I'll have to see if that's true but so far this whole new Power thing is, IMHO, a royal mess. MS gets an "F" on this one.
I made changes to the power management features in vista, and now I am unable to power up. What is the anaswer for reverting back to the previous settings? resetting bois, remove the battery, unplug power cord. remove hard disk etc.. any comments would be good thanks Edward
More interesting posts about Windows XP in next link: http://www.softwaretipspalace.com/MS_Windows_Vista/Tips_And_Tricks.html
While trying to arrive at a standard Intel-based platform for my clients who want Vista, I ran into wake-up problems. The test systems would usually wake up the first time fine, but subsequent "shutdowns" and wake-ups would result in a lockup. I believe I ultimately solved the problem by not installing the NIC and INF drivers.
As far as my desktop PC is concerned power management in Vista sucks as compared to what XP has.
I have a power meter on my PC and with XP I used 0.49 Kwh in a 24 hr period while Vista used i.96 Kwh.
Another 4 hour test this time including the monitor XP used 0.25 KWh and Vista used 0.45.
This is using the same PC different time period same work load.
Bottom line I want the option of having power management work the same way in Vista as it does in XP.
At that rate Vista would cost me an extra 550 Kwh a year for no good reason that I can see.
Hey gamo62: you're better off seeking technical support from the public newsgroups instead of via this blog, as we're simply not equipped to provide it here. Best of luck.
Juat trying Vista Business out on a Dell M70. Sad to see the processor rated 2.1 on the WEI. We do a lot of very insane processing, and tend to always have these laptops plugged in, so we generally turn off PM: under XP, the proc speed was actually 2.13Ghz. Under Vista, no matter how I configure PM, proc speed always shows 797Mhz. Bob Bigmetal isn't going to like the fact that his new toy is running at 1/3 speed...
I'm having problems with resuming from sleep in Vista Ultimate x64 on a Intel D965WH board w/ a Dual Core 2 6600 processor and 2gb dual Channel of RAM. I have an IEEE 1394 drive hooked up, and if it's turned on, the system will not resume. It will go to sleep. If I turn the drive off, then it resumes fine. I have contacted Intel, and they say it is a driver issue. Any suggestions? The Intel quick Resume hotfix did not work. Thanks.
Hey Neil: this blog is not the best place for you to seek tech support; I'd redirect your inquiry to our newsgroups.
I recently installed Windows Vista Home Premium 32bit (OEM) and am getting BSOD on waking from sleep.
I have disabled it for now but I would really like to use this feature. Any news on a patch to fix this?
Hey "Jim Allchin",thx for share
On my Vaio SZ390 (which Sony have not yet released specific Vista drivers for) Power Management isn't bad but the battery life isn't as "advertised" for the device.
Would like more flexibility (or at least confirmation that it's working as I want) - best battery life on battery and full speed ahead on mains, with whatever instant-on strategy it want's to use behind the scenes.
So far I have experienced the hot battery issue a number of times... both from just shutting the lid (which I have set to "sleep") and hitting the power soft-button (which is set to "hibernate") - though I suspect these may be down to the lack of Vaio drivers rather than a Vista problem?
For the sake of completeness, I wanted to mention a minor bug with Vista's power management feature. I already posted to news://msnews.microsoft.com/microsoft.public.windows.vista.general and got in an annoying debate about this with people who don't get it and are too lazy to read the facts. Posting here would be so not worth it were it not for the fact that some people who "discuss" this sort of thing give me indigestion while making me exceedingly indignant, as they tell me to post here, as if posting right here on this blog entry was going to do anything more than posting at the Microsoft newsgroup. (And you guys at Microsoft expose and drop your online feedback and bug report forms back and forth so often I insist that you guys be sure to continue to do what you're already doing which is lurking the one stable and never-going-away feedback resource available to us: the newsgroups.)
I have an Acer Aspire 5050 laptop. I had set Vista up to suspend ONLY if unplugged, but to do nothing when plugged in. But it would still suspend when I closed the lid, even though it was clearly detecting when I plugged in the power adapter. I clicked on Restore Defaults, clicked Apply, then restored the same settings, and the problem was (tentatively) resolved, I was then able to close the lid without suspending. FWIW, I had upgraded from XP MCE. It seems like I went through this hassle before and the problem returned, so I don't know if this will come back again.
Just a minor glitch (no BSOD yet thank goodness) but obviously a Vista glitch nonetheless.
Hey TECH-GURU: You'll find that the performance of Windows Vista has been vastly improved since RC1/RC2 (I've particularly noticed an improvement in waking up from sleep), so just hang on until the retail version is available and I think you'll be pleased.
wake up from Deep sleep state on Vista causes BSOD or some drivers won't work (Audio or Network etc..). Any driver updates or patch could be expected from Microsoft for VISTA on this?
Vista power management gets very confusing when you consider there is no power profile for "On AC = max performance, On Battery = Max Life".
I tried to create one but cannot find where there are power settings for the GUI effects (ie: power saver is ALWAYS in aero basic, and max performance is ALWAYS in aero glass)
My computer never wakes from sleep :(. I have to disable it.
Anas, you can change the Windows power button on the Start Menu to map to shutdown if you really wish to - take a look at the Advanced settings link on the Power Options control panel applet. If you're using a desktop system, bear in mind that a desktop PC will still draw around 2-3 watts even when "shutdown". Using standby is typically about 3 watts as well, but takes only seconds to resume from and saves all your user context.
cwood00, the setting for processor state applies to systems that support ACPI "processor performance states" such as Intel SpeedStep or AMD PowerNow. If your desktop has this technology, then setting the maximum processor state to 50% would indeed cap your processor at state closest to 50% that your particular machine has. Performance states, which are processor core voltage and frequency scaling, are only used when the machine is actually running. When the machine is in sleep, the processor is off, so these states don't apply. If your system doesn't have this CPU performance state capability, then this setting won't have any effect.
HAVE YOU TAKEN A LOOK HERE: http://neosmart.net/blog/archives/299
I have a Dell Inspiron E1505 laptop with an Intel Core 2 1.66GHz CPU, 2GB DDR2 memory, ATI Mobility Radeon X1400 PCIe graphics w/128MB discrete video memory, Intel 3945 802.11 dual band wireless network adapter, and a Hitachi 80GB 7200RPM SATA II hard disk.
Under Windows XP SP 2 MCE I get 5 1/2 hours of battery life with this configuration. With 64-bit Vista RC 2 I barely get 3 hours of battery life. Microsoft hasn't improved power management. They've made it significantly worse.
As I've played with Vista over the past few months I've found this feature to be surprisingly well done. However, it has bitten me multiple times because I usually use remote desktop to log into my work machines if I need to work during off hours. A few times my desktop had gone into hibernate mode and I had to find someone in the office to bring it back to life.
Of course, now I just set all of the machine to stay on all the time, which isn't exactly the right thing.
Unfortuntatly, my experience of RTM, is Power Management is where most of Vista's problems are. It's very unstable, on both my x64 desktop and 32bit laptop, both of which are less than a year old. :-(
I'd happily let vista do the power saving thinking for me, except 75% of the time I press the off button, my computer won't ever come back out of sleep and I just get a fan going and need to restart! Come on companies, get the drivers out.
Does the Windoze platform have anything like this? http://hughsient.livejournal.com/3784.html
I had actually imagined and wished for this exact particular feature when I first used XP's hibernate...thanks MS. All these improvements are great for the desktop. BUT
1. Don't you realize that the moral of the story is laptops end up draining out their batteries faster on Vista than on XP, so maybe next time you should develop a Tablet PC/Laptop/Power efficient SKU. Advise laptop users to turn off Desktop Windows Manager and use Vista Classic for now.
2. Even when hibernated, MS should allow other operating systems to boot. Please you can do this in Vista SP1.
But conneting to computer with remote desktop screws up the Power settings.
Great feature, and thanks very much Jim for the informative article. I have a few questions though..
If I use the 'Power Saver' plan the default setting for the maximum processor state is 50%. Does this mean the cpu will never be allowed to go over 50% while i'm actively using my (desktop) pc? or just while in sleep? Or is this setting overidden because Vista realises that i'm not using battery power?
Sounds great Jim, I know that many PC's are on 24X7 at many companies, and the costs in terms of electricity and environmental costs are substantial so its nice to know that Vista has some new features/tweaks that can lower the TCO, and help the environment.
Makes me want to get rid of my CRT at home and go to an efficient power saving LCD, that will probably have to wait until next Black Friday with my budget though!
It is a really nice job what you did with Windows Vista Power Management. But everytime I click that button, I want my system to shut down. I shut down often. It does not shutdown, but goes to standby and never ever hibernates or sleeps.
This is all nice and well, but still my laptop (Thinkpad T60) runs significantly less long with Vista than it did with XP on batteries. Which, in the end, is the one thing I really care about.