Outlook 2016 CPU usage running continuously at around 100%

Anonymous
2015-07-29T05:38:02+00:00

I recently purchased a Office 365 Business plan, and have installed the desktop Office 2016 apps. I am experiencing continuous high CPU utilization, causing the fan in my MacBook to run much of the time. Activity Monitor shows that Outlook is the culprit.

I have Outlook 15.11.2 and OS X 10.10.  I have one Exchange 2010 (SP2) accounts and two IMAP accounts. All are showing folders up to date, and mail is being sent & received normally.

I haven't noticed any issues with the other Office 2016 applications.

I have already tried creating a new identity and setting up accounts again from there (rather than importing from OUtlook 2011 which I did at first installation), but it did not help.

I have also installed the suite on my iMac, and experience the same issue there, so it is not specific to my laptop.

There is an earlier thread on this issue, started in 2014 and with posts up to mid July this year, with not a single response from MSFT. It is clear there is a bug here, as it stands I am going to have to abandon Outlook 2016 and revert to 2011, so if it can't be fixed I'd like a refund.

Outlook | MacOS | Legacy Outlook for Mac | For business

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Anonymous
2017-03-14T12:50:52+00:00

I tried every option listed in this thread - to no avail.

What worked for me was to turn off Dictation:  (System Preferences\Accessibility\Dictation) 

As soon as I did that, the CPU use returned to normal instantly.

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  1. Jim G 134.1K Reputation points MVP
    2016-12-03T19:26:23+00:00

    Build 15.30 fixes the CPU problem for some users, but not all. When it is available to you, install it. Fast Insiders have the first version of this build already.

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  2. Anonymous
    2016-12-02T21:31:00+00:00

    See also this thread.

    Still broken for me, same symptoms as diespie.

    The solution in that thread above worked for me - turning off auto language detection in Outlook and Word:

    In Word: 

    1. Select "Tools" -> "Language"
    2. Uncheck "Detect language automatically"

    In Outlook: 

    1. Open a new message
    2. "Edit" -> "Language" -> "Language"
    3. Uncheck "Detect language automatically"

    I suspect there is a conflict between the OS setting and where/how MS is looking for the setting.

    Useful answer was found here: https://answers.microsoft.com/en-us/msoffice/forum/msoffice\_officeinsider-mso\_mac/outlook-for-mac-1528-high-cpu-load/5ca4b1f1-e396-49b8-9aad-13467926b9b2?page=2 

    I made the change suggest above just to Outlook (i.e., remove the detect language automatically feature) and then ran Activity Monitor all day.  The results... Outlook CPU usage is back to normal - spending most of the time at 0.1% with nothing going on, and bursting to 10-20% when searching, editing, sending, etc.

    At least from a CPU perspective, this change has made my system (Outlook for Mac 15.28.1 running under running El Capitan 10.11.6 on a late 2013, Retina-based MacBook Pro) usable again. Thanks!

    Now if I could just find a way for bullets to show up in my sent mail the way they looked when I created them, I'd be a really happy camper.  I may be too picky, but if I wanted "∙", instead of "●" I'd have selected it in the first place.

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  3. Jim G 134.1K Reputation points MVP
    2016-11-30T18:22:02+00:00

    Based on comments I've seen in other Q&A on this topic, I think Microsoft has figured out the cause and is planning to release a fix very soon. Fast Insiders will get it first.

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  4. Anonymous
    2016-11-30T13:09:18+00:00

    If I were a Microsoft developer and I couldn't reproduce this problem but wanted to get closer to solving it. . .I think I might be very interested in seeing the thread stack of the active thread.  On Windows, I'd do this with Process Explorer (procexp.exe).  I have no idea how I'd go about this on OS X.  A little googling suggests this http://www.newosxbook.com/tools/procexp.html as a possibility, but that doesn't look like a program that's very friendly to a casual user.

    If a Mac user is experiencing this problem and can't make heads or tails of http://www.newosxbook.com/tools/procexp.html, they might want to find a friend, coworker or other resource that's geeky enough to take them through the process of snapshotting the thread stack.  And then post the results here.

    It's not going to solve the problem, but it's going to make it easier for someone else to solve the problem.  Might not help, but couldn't hurt.

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