High CPU usage when typing a message in Outlook

Question

OS: Win 11 Pro

Office: 2016 Pro

Hi everyone,

CPU activity goes to 16-22% when typing a message in Outlook 2016 and returns to 1 % when typing stops.

Deactivating (all) add-ins and Graphic acceleration did not solve the issue.

Deactivating spell check options did not cure the problem either.

The problem seems to be specific to Win 11 and does not occur on Win 10 OS.

If anyone has any suggestion on how to solve this issue...
PDMC

***moved from Outlook / Windows / Classic Outlook for Windows / For business***

Answer 1

Dear Gabriel,

I did some testing today and although subjective I believe I see the CPU spike more starting with build 17726.20126.

To see if you can confirm this, revert to the build below and test. The build in the steps below is for Current Channel. If you are on a different channel let me know what it is, and I will find the appropriate build. Builds available to revert are on this page, Update history for Microsoft 365 Apps (listed by date) - Office release notes | Microsoft Learn. The revert steps should take about five or so minutes and you will need to close the Office apps.

Steps to revert Office to Current Channel build 17628.20110:

1. Open a Command Prompt in Administrator context.
2. Type or paste the two commands into the Command Prompt window and press Enter after each:

cd %programfiles%\Common Files\Microsoft Shared\ClickToRun

officec2rclient.exe /update user updatetoversion=16.0.17628.20110

Alternate command to those above:

"%programfiles%\Common Files\Microsoft Shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.17628.20110

On my system, switching off text predictions and checking spelling and grammar, which I had already tried during the months before, did not solve the problem, but only changed the CPU usage slightly.

I had also some months ago already tried rollbacks of MS 365 incl. Outlook to versions 2410, 2409, 2408 and 2406, with no change concerning this issue.

You now mention build 17726.20126 (version 2406) as starting point of the issue, but build 17628.20110 (version 2405) should be OK. By the way, here's the version history again: https://learn.microsoft.com/de-de/officeupdates/update-history-microsoft365-apps-by-date?redirectSourcePath=%252fen-us%252farticle%252fae942449-1fca-4484-898b-a933ea23def7

And here's the offical rollback how-to: https://support.microsoft.com/en-us/topic/how-to-revert-to-an-earlier-version-of-office-2bd5c457-a917-d57e-35a1-f709e3dda841

So I will try the rollback to 2405 soon and let you know. If it should work, that would be at least a work-around - but the bug must nevertheless be fixed by Microsoft, because we shouldn't stay at an old version too long.

Answer 2

Gabriel's work-around really seems to work and stops the high CPU usage while typing a message in Outlook!

I tried rollbacks to version 2405, build 16.0.17628.20110 (first build of 2405) as well as build 16.0.17628.20164 (latest build of 2405), and with both, the high CPU usage did not appear again up to now. To be verified over the coming days, but this looks very promising!

For the rollback, I would recommend build 16.0.17628.20164 (latest build of 2405), because in comparison to 20110 (first build of 2405) which Gabriel mentioned, 20164 includes some later security fixes and, most of all, it already includes some major user-interface updates (for example the new rounded menu ribbon) which 20110 is missing. So version 2405, build 16.0.17628.20164 has already the same look as the current version 2502, whereas version 2405, build 16.0.17628.20110 still has the older look.

Hopefully, the CPU usage really does not appear again after the rollback. And hopefully, Microsoft will fix this bug very soon so that everybody can receive current updates again.

By the way, there had been a very similar bug already some time ago, from version 2105 to 2301 (it took MS over 1,5 years to finally fix it...). At that time, the high CPU usage appeared when opening attachments in Outlook: https://answers.microsoft.com/en-us/outlook_com/forum/all/outlook-causes-high-cpu-usage-for-2-3-minutes-each/fa903250-4bd2-4517-942c-fe77b4c6f3c3

By the way, for those who speak German, there's another thread for this issue on a German discussion board: https://thinkpad-forum.de/threads/outlook-365-seit-2-3-wochen-pl%C3%B6tzlich-sehr-oft-hohe-cpu-last.230167/page-5#post-2408544

Answer 3

@dark-rider,

Was your support case opened through the M365 Admin Portal? Does it have a number such as 2503060010001954? If it's a commercial case, I would like to see about getting this routed to classic Outlook support and get this escalated for a hotfix request. If you still have the case number, please share it.

Also, there is another workaround that should work for this issue. You can switch Office channels to Semi Annual channel. The reason I suggest this is it will ensure you are on the latest build, so you have all the security updates. Also, this channel is the slowest to get feature changes and for example does not have Text Predictions. I tested this channel, and it does not spike CPU when typing for me.

I will post some steps tomorrow to switch channels to Semi Annual channel. There is a way to do this with one registry key but I want to test it to double check it works as expected, Use a registry command to install Microsoft 365 Insider on Windows devices - Microsoft 365 Insider | Microsoft Learn. The channel to use with the registry key is SemiAnnual.

Answer 4

Dear Gabriel,

Matth22 (with his posting on the bottom of page 3 of this thread) reported that he was intensively working with Microsoft on this issue. So he should have a ticket number, could you ask him and if possible escalete it for a hotfix request?

Concerning SemiAnnual Channel: Isn't this only possible for Enterprise customers? When I understand it right, this channel dispenses with functional upgrades, but just offers security fixes, right? So in comparison to the rollback to 2405, you would get the latest security fixes further on. There seem to be three different SemiAnnual versions (2308, 2402 and 2408). Which one to choose and how? 2308 and 2402 should be OK, but 2408 is newer than 2405 and should include the bug again? Isn't the SemiAnnual channel upgraded every 6 months, so that this would only fix the problem temporarily until the next upgrade comes?

Answer 5

My ticket number was #2412110040013308. It seems MS closed my ticket and isn't responding to emails when I reply in that conversation. I may have worn out my welcome in that thread.