kernel_task hogging 300% CPU

Question

Hi all, I hope someone might be able to help. My Macbook Air has been misbehaving since yesterday evening. It&#x27;s sluggish, the fan is running very loudly and constantly and kernel_task seems to be using about 250-300% CPU. I&#x27;ve looked back through previous threads, and seen people with similar issues, however none the proposed solutions seem to have worked for me. I&#x27;ve tried an SMC reset, restarting it in boot made (it stays the same), as well as the proposed "fix" here - http://www.rdoxenham.com/?p&#x3D;259So far, nothing at all seems to have worked and it&#x27;s making me crazy. I&#x27;d be really appreciative if anyone has any possible solutions. EtreCheck Report:EtreCheck version: 2.2 (132)Report generated 7/1/15, 4:30 PMDownload EtreCheck from http://etresoft.com/etrecheckClick the [Click for support] links for help with non-Apple products.Click the [Click for details] links for more information about that line.Hardware Information: ℹ️    MacBook Air (13-inch, Mid 2013) (Verified)    MacBook Air - model: MacBookAir6,2    1 1.7 GHz Intel Core i7 CPU: 2-core    8 GB RAM Not upgradeable        BANK 0/DIMM0            4 GB DDR3 1600 MHz ok        BANK 1/DIMM0            4 GB DDR3 1600 MHz ok    Bluetooth: Good - Handoff/Airdrop2 supported    Wireless:  en0: 802.11 a/b/g/n/ac    Battery: Health &#x3D; Normal - Cycle count &#x3D; 166 - SN &#x3D; D86441632TBF90JAZVideo Information: ℹ️    Intel HD Graphics 5000        Color LCD 1440 x 900System Software: ℹ️    OS X 10.10.3 (14D136) - Time since boot: 0:7:26Disk Information: ℹ️    APPLE SSD SM0512F disk0 : (500.28 GB)        EFI (disk0s1) &lt;not mounted&gt; : 210 MB         Recovery HD (disk0s3) &lt;not mounted&gt;  [Recovery]: 650 MB         Macintosh HD (disk1) / : 499.08 GB (262.27 GB free)            Encrypted AES-XTS Unlocked            Core Storage: disk0s2 499.42 GB OnlineUSB Information: ℹ️    Apple Internal Memory Card Reader     Apple Inc. BRCM20702 Hub         Apple Inc. Bluetooth USB Host Controller Thunderbolt Information: ℹ️    Apple Inc. thunderbolt_busConfiguration files: ℹ️    /etc/hosts - Count: 57Gatekeeper: ℹ️    Mac App Store and identified developersLaunch Agents: ℹ️    [not loaded]    com.adobe.AAM.Updater-1.0.plist [Click for support]Launch Daemons: ℹ️    [loaded]    com.adobe.fpsaud.plist [Click for support]    [loaded]    com.adobe.SwitchBoard.plist [Click for support]    [running]    com.fitbit.galileod.plist [Click for support]User Launch Agents: ℹ️    [loaded]    com.adobe.AAM.Updater-1.0.plist [Click for support]    [running]    com.akamai.single-user-client.plist [Click for support]    [loaded]    com.google.keystone.agent.plist [Click for support]    [running]    com.spotify.webhelper.plist [Click for support]User Login Items: ℹ️    iTunesHelper    Application  (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)    Dropbox    Application  (/Applications/Dropbox.app)    Fitbit Connect Menubar Helper    Application  (/Applications/Fitbit Connect.app/Contents/MacOS/Fitbit Connect Menubar Helper.app)    RescueTime    Application Hidden (/Applications/RescueTime.app)    EOS Utility    Application Hidden (/Applications/Canon Utilities/EOS Utility/EOS Utility.app)Internet Plug-ins: ℹ️    FlashPlayer-10.6: Version: 18.0.0.194 - SDK 10.6 [Click for support]    QuickTime Plugin: Version: 7.7.3    Flash Player: Version: 18.0.0.194 - SDK 10.6 [Click for support]    AdobePDFViewer: Version: 10.1.1 [Click for support]    Default Browser: Version: 600 - SDK 10.10    OfficeLiveBrowserPlugin: Version: 12.3.6 [Click for support]    Silverlight: Version: 5.1.40416.0 - SDK 10.6 [Click for support]3rd Party Preference Panes: ℹ️    Akamai NetSession Preferences  [Click for support]    Flash Player  [Click for support]Time Machine: ℹ️    Time Machine not configured!Top Processes by CPU: ℹ️        10%    Safari        10%    fontd(2)         8%    mdworker         7%    WindowServer         2%    loginwindowTop Processes by Memory: ℹ️    615 MB    kernel_task    98 MB    mds_stores    98 MB    iconservicesagent(2)    90 MB    Dropbox    90 MB    SafariVirtual Memory Information: ℹ️    4.60 GB    Free RAM     3.40 GB    Used RAM     0 B    Swap Used Diagnostics Information: ℹ️    Jul 1, 2015, 04:19:16 PM    Self test - passed    Jul 1, 2015, 04:09:04 PM    /Users/[redacted]/Library/Logs/DiagnosticReports/RescueTime_2015-07-01-160904_[ redacted].crash

Linc Davis · Answer

The kernel is using excessive processor cycles. Below are some possible causes for the condition.ThrottlingWhen it gets high temperature readings from the hardware, or low voltage readings from the battery of a MacBook, the kernel may try to compensate by interrupting the processor(s) to slow them down and reduce power consumption. This condition can be due to:☞ a buildup of dust on the logic board☞ high ambient temperature☞ a worn-out or faulty battery in a portable☞ the malfunction of a cooling fan, a temperature sensor, a voltage sensor, or some other internal componentNote that if the problem is caused by a sensor, there may be no actual overheating or undervoltage.If the computer is portable, test with and without the AC adapter connected. If kernel_task hogs the processor only on AC power, charging is causing the machine to heat up. That behavior may be normal for some models, but it may also be an indication of a hardware fault.Apple Diagnostics or the Apple Hardware Test, though not very reliable, is sometimes able to detect a fault. For more thorough hardware testing, make a "Genius" appointment at an Apple Store, or go to another authorized service provider.If nothing is wrong with the hardware, then whatever you can do to improve cooling may help.Installed softwareUser-installed software that includes a device driver or other kernel code may thrash the kernel. That category includes virtualization software, such as Parallels and VMware, as well as most commercial "anti-virus" products. Some system-monitoring applications, such as "iStat," can also contribute to the problem. You can test for this possibility by completely disabling or removing the software according to the developer&#x27;s instructions, or starting in safe mode. Note, however, that disabling a system modification without removing it or testing in safe mode may not be as easy as you think.Corrupt NVRAM or SMC dataSometimes the problem is cleared up by resetting the NVRAM or the SMC.External displayConnecting an external LCD display to some MacBook Pro models while the lid is open may cause this issue. If applicable, test by closing the lid or disconnecting the display. You might get better results with a newer LED display.