Questions about with tracking and reducing power-drain for computers or devices.

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16
votes
2answers
8k views

Mountain Lion sleeps too aggressively

For me, Mountain Lion always seems to sleep whenever there is no user action, even when the computer is still doing something. In my case it always sleeps in the middle of running a batch operation in ...
10
votes
5answers
13k views

Mountain Lion aggressively hibernates

Recently, my MacBook Pro (mid 2012, 15 inch, 10.8.2) has started going into what seems to be hibernate mode after several hours asleep, whether it's plugged in or on battery. When I unplug it, it ...
9
votes
1answer
34k views

What is the “wake for wifi network access” setting in energy preferences?

Can anyone explain the "wake for wifi network access" setting in energy preferences for me? I do not understand it.
9
votes
5answers
9k views

kernel_task consumes 500% CPU on AC power, sometimes

Typically, my kernel_task process uses 1-4% CPU and 100-700MB of memory. However, sometimes when I have the power adapter plugged in, the CPU usage jumps to around 500% (8 cores) and stays there until ...
8
votes
1answer
847 views

How can I tell whether a drive is asleep?

Is there an application or command-line utility for Mac OS X to query a hard-disk to see if it is 'asleep' or 'awake' right now? (i.e. as controlled by Energy Saver / pmset disk sleeping preferences). ...
7
votes
2answers
3k views

How to not let the system sleep when putting display to sleep with Ctrl+Shift+Eject in Mountain Lion?

In Lion I always used Control ⌃+Shift ⇧+Eject ⏏ to put my display to sleep when I walked away from my computer. The system would continue running and not go to sleep. Now in Mountain Lion when I put ...
6
votes
2answers
1k views

What is the difference among the various event schedulers for OS X / Darwin?

I'm confused about the differences among the three (that I know of) tools for scheduling running of code on OS X / Darwin: cron launchcd pmset I understand that cron is largely deprecated, but it ...
6
votes
1answer
5k views

High fan speed and CPU temp with low CPU usage?

I've been having intermittent fan speed and high CPU temperature when my CPU usage is nearly 0%. I don't run any weird apps. If I put my computer into sleep mode and wake it back up, this fixes the ...
6
votes
1answer
4k views

What do the “Energy Impact” numbers displayed in the new OSX 10.9 mean and how are they calculated? [duplicate]

I love the new energy tab in OSX 10.9 mostly because I love data about my machine. I'm curious how the energy impact is calculated, and what the number represents. It seems clear from using the OS ...
5
votes
1answer
10k views

How to make a Mac (Macbook Pro) not hibernate?

I have already set in the Energy Saver of System Preferences that Computer sleep: on Battery Power, Never when plugged in, Never But still if I close the cover of the Macbook Pro ...
5
votes
1answer
12k views

Disable Stand By Mode on Retina MacBook Pro?

I learned that the retina MacBook Pro has a Deep Sleep Mode that is initiated when left idle for a long time. This, however, causes my laptop to take about 3-5 seconds to wake up after it sleeps, such ...
4
votes
2answers
58 views

Is there a way to tell which OS X processes are using the most power over time? [duplicate]

My Android phone comes installed w/ an app that graphs out power usage of various components over time, so it's clear that the screen is the biggest user, followed by the phone, followed by Facebook ...
4
votes
1answer
101 views

Energy saver: do the battery settings apply during charging?

I have my Macbook pro 17 (early 2011, OSX 10.6.8) set to turn off the display at 30 minutes on AC, and 10 minutes on battery. I've noticed recently that if the battery is charging (the little battery ...
4
votes
4answers
600 views

Is there a way to shutdown mac when screen is turned off?

I have a mac mini, which is connected to a TV using HDMI cable. TV & mini are connected to separate power source, so that I can shutdown TV and mini independently as required. Primary use of mini ...
4
votes
3answers
11k views

Difference between autopoweroff and standby in pmset

I just got a new Retina MacBook Pro 15". After getting some downloads interrupted due to the computer going to sleep (even on AC power), I started looking at the man page for the pmset command. I did ...
3
votes
2answers
320 views

Can I use a Mac mini without the power brick?

I don't have the power brick for my Mac mini with me but I have cord that plugs into the back of it, can I use it without and plug directly into the wall? Any harm? The model is A1347
3
votes
1answer
5k views

How much power does a mac mini uses?

I would like to know how much power would a mac Mini consume per month/year if: always powered, but under very low load web server OS, probably Ubuntu two drives: one SSD and one HD. model Early ...
3
votes
4answers
2k views

Is InsomniaX working on Mavericks?

It seems to me that InsomniaX, a utility to let a MacBook stay awake when the lid is closed, is not working on Mavericks. Can anyone confirm for me?
3
votes
2answers
28 views

Don't charge iphone when plugged into macbook?

Is it possible to temporarily keep your iPhone from draining the macbook battery? When I'm out and about I sometimes want to connect my [nearly empty] macbook to my [not so empty] iphone so I can ...
3
votes
2answers
9k views

While my MacBook sleeps, the network drops off?

I have just moved over to a Macbook Pro from my old Macbook. Thanks to the Migration Assistant, it was an easy task, but I am now having an annoying issue: I have both computers on with all the same ...
3
votes
2answers
858 views

Disable Spotlight indexing, save battery life

I am using my laptop with very limited battery availability. I need to save as much battery as possible. I would like to disable Spotlight indexing, how do I do that? What else should I disable, ...
3
votes
2answers
371 views

OSX Mountain Lion: Automatically restarts after showing screen saver a certain amount of time

Since I upgraded to Mountain Lion it happens to me every day when I enter the screen saver while having lunch it tries to restart the computer. I don't have any clue why this happens. If there is ...
3
votes
1answer
212 views

Do Solid State Drives need Power Management? Do they need sleep?

Is there any positive (or negative) to checking the power management option "Put hard disks to sleep" when I only have a SSD drive installed? Is there any difference if I'm connected to another ...
3
votes
3answers
813 views

Macbook Pro random shutdown

Has anyone experienced this problem? Does anyone have a solution? I have scoured the internets for solutions and found many different answers. I am on a Macbook Pro 6,1. The one that has worked for me ...
3
votes
1answer
350 views

Why Does My MBA Close All My Apps After 5 Mins Idle?

Sometimes if I walk away from my MBA without locking the screen and I return I'll be faced with a login screen. Once I login all my apps I had open are now closed. Sometimes I'll close my MBA lid and ...
3
votes
1answer
715 views

How to know if the System Management Controller (SMC) has been reset?

I've recently uninstalled Fan Control, and one of the steps of the uninstallation is that I need to reset the SMC. So I've done that according to the instructions from the Apple website, however how ...
3
votes
1answer
400 views

iMac sleeping even when set to never sleep

Running 10.7.5, I've got a fairly new iMac (6 months old) 27", set to never sleep, yet when I got in to work this morning it was asleep. How to fix this? Output from pmset -g in Terminal: Active ...
2
votes
4answers
4k views

Limit processor speed like in Windows

In Windows (Linux too), you have the very useful "Power saver" mode that limits the maximum frequency at which your CPU runs. Is there something similar in OS X?
2
votes
2answers
641 views

SSH to Macbook works when lid closed (and plugged in to power)

I noticed that my PuTTY session to my MacBook (which is now on Mavericks 10.9.3) seems to stay alive with the clamshell closed so long as the power cable is plugged in to the laptop. This can be seen ...
2
votes
1answer
889 views

OS X Mountain Lion: Change resolution automatically when on battery

I have a rMBP running OS X 10.8 Mountain Lion. I normally use the display at a 1680x1050. Is there a way to have the display automatically change resolution to the default retina when on battery, and ...
2
votes
2answers
9k views

MacBook Pro won't power on after SMC reset

Some water was spilled on the table and came in contact with my wife's Mid 2009 MacBook Pro near the MagSafe adapter causing the MBP to shut itself off. Based on some recommendations from the ...
2
votes
1answer
2k views

How much power can be drawn from the lightning connector by a external device?

How much power can be drawn from the iPhone/iPad lightning connector by a external device? Update: The use case is a audio-related device for iPhone/iPads. It would require around ~100 mA at 3,3 ...
2
votes
2answers
360 views

Don't Sleep Network Connection / VPN

If I let my computer sleep my VPN connection seems to die. Mac shows it as still being up, but nothing over the VPN works until I reconnect and disconnect. I am happy to have a my monitors sleep, but ...
2
votes
1answer
794 views

How to add sites to the Safari Power Saver exclusion list?

In Safari, a feature I really like is that flash plugins are automatically blocked by default and you have to click in order to start the flash plugin (see, e.g., ...
2
votes
1answer
519 views

During an iTunes sync, are MacBooks prevented from going into sleep mode?

I want to know this as I sometimes leave my iPhone unattended while syncing and I want to make sure that there's no cut off to the iPhone sync.
2
votes
1answer
952 views

When should I reset the SMC on a Mac?

I want to know when I should reset the SMC on a Mac. I have a very quirky G5 and was wondering if resetting the SMC would fix some of its problems.
2
votes
1answer
135 views

Sleep timeout missing from the energy saver preferences

I have two Macbook Pros running on Yosemite. The first one is a 17 incher from 4 years ago. I'm able to set the time that it sleeps. The second one is a 15 incher retina made this year. In its energy ...
2
votes
1answer
74 views

Early 2011 MacBook Pro SMC firmware update question

OS has been upgraded to Mavericks. Can I still run the SMC firmware update 1.7 said to be for OS 10.75 and 10.82? Would it hurt anything to try this firmware update with the later OS?
2
votes
1answer
10k views

MacBook Pro not responding to power button

My Mac wont start up even with full battery and charger plugged in... There is no sound, no screen or any disk movement. The same thing also happened a few weeks back and when I took it to the repair ...
2
votes
1answer
206 views

How to pesistently configure a Macmini4,1 to boot after power failure?

I do have a Macmini4,1 (2010) and I want to use it as a server so it will always start even after a power failure. Please remind that I am running Ubuntu on it, not OS X. Still, based on what I ...
2
votes
1answer
175 views

Stop auto-dimming automatically

I've noticed my Mac didn't retain the brightness I set with the keys. How do you stop it from auto-dimming?
2
votes
3answers
3k views

How to keep Mac alive during internet connection/download

Since version 10.8.1, my Mac cancels the wifi connection and switches to standby mode, despite download. I can remember that the one advantage of the mac was that i don't have to do anything for ...
2
votes
1answer
413 views

Is my SMC damaged?

I have a Macbook Pro running 10.9.3 (13D65), Boot ROM Version: MBP55.00AC.B03 SMC Version (system): 1.47f2 The fans are always running at full rpm and the kernel task used to take up 90% of the ...
2
votes
1answer
326 views

MacBook Pro 5,1 will only turn on after SMC reset

Resetting the SMC every time the machine is turned off is the only way to turn it back on and when it is on the fans run at max speed etc. etc. (SMC issues). Have tried to swap out HDD and RAM. ...
2
votes
0answers
867 views

MacBook Pro will boot only after a SMC reset

I replaced the hard drive in my MacBook Pro (mid-2010) with a SSD one. I installed Mac OS X 10.9. At first the installer wasn't able to find the new SSD drive, because of a error: "SerialATAPI device ...
2
votes
2answers
598 views

Mac wakes on scheduled power event that recreates itself every day

At 2:14 every morning, my Mac wakes. Looking at the logs, I see it's a scheduled event, but nothing shows up in System Preferences > Power. When I go to terminal, and run pmset -g sched, I see ...
2
votes
0answers
56 views

Darken Background Illumination When There is No Windows

I have a MBP in a dualscreen setup with the laptops display as secondary. I'd like to know if there is an application that dims the display's illumination when there is no window drawn on the laptop.
1
vote
3answers
2k views

Prevent iMac from sleeping, for VPN login?

We have an iMac in the office, and I have been getting inconsistent access when trying to log in to it. The firewall isn't going down, since I can connect to the VPN. After discussing it with the ...
1
vote
1answer
479 views

Preventing iOS devices from sleeping

Is there any straight forward way of preventing an iOS device from sleeping? The only way I found so far is to open the "Music" app and start playing (and muting the volume if I don't really want to ...
1
vote
2answers
373 views

iMac display wakes up even when no one is using it

I have my iMac set to set the display to sleep after 15 minutes. I notice at night that, even when no one is touching the computer, the display will come on for a while and then to go back to sleep ...