Questions tagged [power-management]

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

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35
votes
3answers
124k 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.
27
votes
4answers
58k 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 ...
22
votes
2answers
20k 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 ...
18
votes
6answers
23k 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 ...
17
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 ...
17
votes
4answers
27k 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 ...
12
votes
5answers
16k 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 ...
12
votes
1answer
19k 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 so if I close the cover of the Macbook Pro running ...
12
votes
1answer
22k views

Significance of IODisplayWrangler in power management assertions

When I check my power management assertions (MacBook Pro running macOS Sierra), I see the following line: $ sudo pmset -g assertions ... Idle sleep preventers: IODisplayWrangler What is ...
10
votes
1answer
2k views

Is there a way to force “low power” graphics?

Is there a plist or hidden config to set my graphics/energy preference to "Always use low power/ integrated graphics"? Seems like energy saver preferences only allow choosing between: Smart auto ...
8
votes
6answers
12k views

Why does my laptop shut down overnight?

Whenever I leave my MacBook Pro (Retina, 13-inch, Early 2015) unattended (plugged in, or not) overnight (or for long periods of time) it shuts down by itself. When I open the lid it boots up to the ...
8
votes
1answer
24k 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 ...
8
votes
1answer
5k views

What can cause the SMC to repeatedly need to be reset?

I currently have a problem with my MacBook Pro where the SMC keeps getting screwed up and needing to be reset. The result is always that my keyboard and trackpad become useless, and I have to use an ...
8
votes
3answers
8k 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 ...
8
votes
1answer
2k 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). ...
8
votes
2answers
8k views

MacBook discharging while plugged in under load

I have the latest Retina MacBook Pro MacBookPro11,2 I quite often have the CPU at about 400%-500% usage (e.g. 4-5 cores at 100%) and also do GPU intensive tasks. While this is happening, the battery ...
8
votes
5answers
2k views

Does the iPhone 6 “CPU-throttling” feature stop after the battery is replaced?

There is recent news (acknowledged by Apple) of a feature in some software versions of iOS that reduces the current usage of the iPhone6 and 6S when the battery ages and is less able to supply current,...
7
votes
2answers
14k views

Removing the sleepimage file in /var/vm in macOS permanently

I run high sierra, and the large private/var/vm/sleepimage file has been bothering me. My computer has 16 GB of ram, which means sleepimage takes up 16 GB on my drive. I have read tutorials on how to ...
7
votes
1answer
14k 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 ...
7
votes
1answer
6k views

Preventing Safari background tabs disconnecting from server

Safari puts background (i.e., currently not selected) tabs to sleep. If that tab is on a website that requires an active connection to its server, such as chat apps (Slack, Google Talk, etc.), then ...
7
votes
2answers
2k 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 is ...
7
votes
1answer
12k 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 ...
7
votes
2answers
8k views

How can I prevent Mac terminal ssh from disconnecting when the screen is automatically turned off?

I frequently use ssh on my MacBook to connect to other servers and run long-running commands there. When I do this, I leave the lid open to let it run, but then if I don't go to make coffee or ...
7
votes
1answer
4k views

CPU stuck at 0.8Ghz on iMac late 2013 2.7Ghz because of kernel_task

I know it seems like this question is like the dozens of other questions about CPU overheating and kernel_task overloading it, but nope. I found an iMac (yep, found it. In the trash). I fixed it (...
7
votes
11answers
18k views

MacBook Pro 2016 (Touch Bar) in “Critical Update” loop

So my MacBook Pro has been experiencing some weird issues after an unprompted and unexpected shut down. When I turned it back on, it claimed there was a “critical software update” and asked to choose ...
7
votes
2answers
7k views

Mac Sleep Wake Failure

I've got an iMac running High Sierra, and over the last couple of months it has developed a problem where it spontaneously reboots itself about once a day. The reboots always occur when the iMac is ...
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 ...
7
votes
1answer
6k 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 ...
6
votes
1answer
1k views

Persistently or aggressively enabling Low Power Mode

I love the Low Power Mode feature. When I'm travelling or in other situations where reliable communication is more important than user experience, I want to always have it enabled, sometimes for days ...
6
votes
2answers
8k 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
4answers
616 views

Battery Menu Bar doesn't show Time Remaining

Kinda a unique issue here I haven't been able to find the solution to on Google. As you can see in the screenshot below, my battery menu doesn't give me time remaining on Battery. Not even System ...
6
votes
3answers
16k views

How to keep monitor off when logging in remotely

I'm managing an 8-core mac server (fully updated to Mac OSX 10.8.4, all other software is up to date). Multiple users can login remotely to use the machine. Whenever someone logs in remotely, the ...
6
votes
2answers
3k views

Ignore “prevent sleep” request from a specific app

I sometimes have the problem that my macbook won't sleep, even with the lid closed. After some investigation I tracked the problem down to Spotify app; when the app is open, even if no song is playing,...
5
votes
1answer
17k views

What risks from an SMC reset?

My mac is always quite hot and the fans are often at full speed even with moderate activity. Also, when I plug in the external monitor, the computer becomes very sluggish and kernel_task starts taking ...
5
votes
1answer
1k views

MacBook Pro 2016 going to sleep after one minute no matter what my settings are

My energy saver preferences are as follows: However, no matter what I set the slider to, my MacBook Pro is going to sleep after one minute. What is wrong here?
5
votes
2answers
2k views

Automatically Inhibit sleep while transferring files over the network?

I was transferring some files over the network and my macbook pro just fell asleep. I had the "Wake for network traffic" in Preferences>Energy checked. I am using High Sierra. It doesn't sound like ...
5
votes
1answer
2k views

Can't hibernate computer MacOS Mojave, no pmset “standby” option

I have a Mid-2009 Macbook Pro 17 inch (5,2), with MacOS Mojave 10.14 installed. I want to enable hibernation (or standby, or deep sleep, or safe sleep) in order to power off the RAM when in sleep mode....
5
votes
0answers
2k views

Disable wireless power save

Is there a way I can disable the power saving functionality of the wireless in OS-X Sierra (10.12.6)? The issue I'm trying to address is where the wireless goes to sleep and wakes up every few ...
4
votes
4answers
1k views

“this computer has been scheduled to go to sleep” when none is set

Simple question- My mac regularly & seemingly randomly tells me it has been scheduled to go to sleep automatically- usually (I think) right after I wake it up. I have no schedule for automatic ...
4
votes
2answers
94 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
2answers
26k 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 ...
4
votes
1answer
116 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
2answers
27k 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 internet,...
4
votes
1answer
237 views

My computer wakes up at 5:59:39 every morning. How do I stop that from happening?

For some reason my 2017 iMac running macOS 10.14.6 keeps waking up from sleep at exactly 5:59:39 AM every morning. If I look at the logs using pmset -g log at this time it consistently reports: 2019-...
4
votes
3answers
2k views

Mac fan speeds really high

I am using istats to see the speed of my fans: I ran a diagnostic by holding down d during a restart and it came up without any errors. I've also reset pram and the readings are still really high. Is ...
4
votes
4answers
2k 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
1answer
3k views

Mac doesn’t go to sleep after inactivity

Before updating to Mavericks, my Mac would go to sleep after 15 minutes of inactivity, which is usually 10 minutes after I turn the screens off using Shift+Ctrl+Eject. However, since the update, the ...
4
votes
2answers
1k views

Mac turns off the power supply when it sleeps

I'm send my laptop to sleep ( -> Sleep) and when I open it later, it starts loading system from the beggining as if I powered off it. I lose progress in my work because of this. I don't found where I ...
4
votes
2answers
4k views

MacBook Pro randomly waking up from sleep after Catalina update

Since the upgrade to macOS Catalina 10.15.0, I've noticed that my MacBook Pro is randomly waking up from sleep. I use the MBP connected to an External display, BT mouse (MX Master), an external ...
4
votes
1answer
951 views

Macbook Pro 2018 battery not charging dodocool 7-in-1 hub suspected

I am having a version of the battery not charging issue on my Macbook Pro 2018 (13-inch, Four Thunderbolt 3 Ports). The symptoms are somewhat different from related issues, such as in this post. I am ...

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