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Questions tagged [power-management]

The process by which some operating systems will attempt to conserve energy.

May include spinning down disks or fans during idle time. May also effect monitors and entire systems.

Power management system usually implement selectable policies such as conservative or performance.

Primarily relevant to laptops where battery life is an issue though may also refer to turning off monitors to avoid screen burn-in.

See also hibernate and sleep.

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How do I check when the computer is being put to sleep or wakes up?

I want to make my program aware of the computer being put to sleep or waking up from sleep, possibly have an event that is triggered when either of these occur. Is this possible?
esac
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Controlling simple relay switch via USB

I'm looking to control a mains powered light from a simple relay switch connected via USB to the computer. The relay switch isn't even a USB device, it's just a simple switch that requires the USB voltage to turn it on. When the voltage drops below…
Matt
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Android battery usage report for developers

On Gingerbread users can report apps for their battery usage, by going to Settings -> About phone -> Battery use, and then tap on a specific app. My question is, as a developer where can I see these reports? They seem very useful because they…
Erdal
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Can I get a notification whenever the user interacts with an Android device?

Is it possible in Android API level 15 to receive a notification whenever the user does anything that keeps the device awake - in effect, whenever PowerManager.userActivity() is called? (Bit of background: I'm working on a large Android app for a…
Mark Whitaker
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MacOSX 10.8.2: How to clear unwanted power-management assertions?

There are some programs that run under MacOSX Mountain Lion which are now (since installing 10.8.2) causing unwanted power-management assertions to be set. I'm looking for a way to clear assertions like these. Here's one example: one or more of…
HippoMan
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how to measure and improve battery use in iPhone/iPad game (Android also)

My game uses too much battery. I don't know exactly how much it uses as compared to comparable games, but it uses too much. Players complain that it uses a lot, and a number of them note that it makes their device "run hot". I'm just starting to…
M Katz
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How to read the number of battery charges?

as mentioned above, I want to get the total number of battery chrarges. The batery Intent I'm already using only shows me Level, Voltage, Temperature ... but not the total loading cycles.
Tobias
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How can I programmatically stop a notebook battery from charging?

There is some easily available information on finding the status of a battery, or whether it's charging or not. (GetSystemPowerStatus API or System.Windows.Forms.SystemInformation.PowerStatus). I want to be able to stop a battery from charging based…
Marcel
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Uses of the monitor/mwait instructions

I happened to stumble upon these two instructions - mwait and monitor https://www.felixcloutier.com/x86/mwait. The intel manual says these are used to wait for writes in a concurrent multi-processor system, and it made me curious what types of…
Curious
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Off screen rendering when laptop shuts screen down?

I have a lengthy number-crunching process which takes advantage of quite abit of OpenGL off-screen rendering. It all works well but when I leave it to work on its own while I go make a sandwich I would usually find that it crashed while I was…
shoosh
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Is it possible to detect Power Nap / DarkWake mode in OSX

I have a daemon process started via launchd. This will be running even during DarkWake and has no time to finish before OS X goes back to sleep again. I can think of the following solutions, but didn't find a way to achieve this. Don't make this…
user12345
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how to hook to events / messages in windows using python

in short: i want to intercept suspend/standby messages on my laptop, but my program doesn't receives all relevant messages. background: there's a bug in ms-excel on windows xp/2k, which prevents system suspend if a file is opened on a network/usb…
Berry Tsakala
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Is memory latency affected by CPU frequency? Is it a result of memory power management by the memory controller?

I basically need some help to explain/confirm some experimental results. Basic Theory A common idea expressed in papers on DVFS is that execution times have on-chip and off-chip components. On-chip components of execution time scale linearly with…
Safayet Ahmed
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C#: How to prevent a laptop from going into Stand-By

How can I do this in a C# program? I'm pretty sure it should be possible, since various media programs for example do this so the computer doesn't go into stand-by while watching a movie, etc. So, if I for example create a plain and basic WinForm…
Svish
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How can I hibernate a Google Compute Engine server?

I'd like to use a GCE server and VNC to run some desktop programs I've written. However, I'd like to not have the GCE server running all the time (to save money) and I'd like to have the setup of my VNC desktop persisted (to save time). It seems…
Thomas Johnson
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