High CPU usage when typing a message in Outlook

Dear Gabriel,

today I experienced the Outlook GPU (not CPU) bug again, as every few days, with Monthly Enterpise Channel 2503 (18623.20266):

• Sometimes suddenly high GPU load of about 30-50% by DWM.exe stays permanently, as long as Outlook is running.
• If you quit and restart Outlook, the permanent GPU load has gone, but as soon as you work with Outlook and move the mouse cursor over things in Outlook, GPU load still much higher than normal. Even if you just mouse-over the close-button of task manager while Outlook is open, GPU load temporarily rises quite high.
• The only way to get rid of Outlook-caused GPU-load for a while is to restart Windows.

This massive GPU load does not make the fan run, as the CPU bug did, but it also slows down the system significantly.

As I told you, I couldn't yet find a 100% working trigger for reproducing this GPU bug in Outlook, but one thing is striking: If you move the mouse cursor over Outlook's e-mail folder list (normally left column in Outlook), GPU load is temporarily very much higher than when you move the mouse cursor over other things like calendar entries in Outlook or objects in other apps than Outlook.

Version 2405 did not yet have this GPU bug.

I also updated to version 2503 build 18623.20266 (Monthly Enterprise Channel), and I have to report that the GPU (not CPU) bug also still exists. It was not in 2405.

Not always, but quite often Outlook causes the GPU to run permanently with high load. If you quit and restart Outlook, the GPU load is no more permanently, but still much higher than normal every time the mouse cursor moves over Outlook. The only thing that helps (for a while) is to restart the whole PC/Windows.

I still couldn't find a certain trigger for this further bug, but showing certain e-mails or the calendar, especially after longer idle times, seem to be a possible trigger.

Outlook is more and more not for productive work, but for beta testing, also in not-beta channels, and that always again over many months or even years until the bugs get acknowledged at all and fixed (Microsoft makes it nearly impossible for users to report bugs and to be taken serious)... It's a desaster with this piece of software.

Hi Gabriel I've had that option turned off for a while so that's not the issue. More CPU spiking again today. This really needs to be fixed properly and quicker.

This past week we had an issue where the Text Predictions feature went missing, Text predictions unexpectedly become unavailable and are missing in Outlook options - Microsoft Support. I'm not sure if that could have exacerbated the issue but that feature is now back available. If you are not using Text Predictions, I would turn it off and that may help minimize the CPU usage.

To turn off Text Predictions:

1. Click File > Options > Mail.
2. Under Compose messages, uncheck Show text predictions while typing.

Hi Gabriel, I updated to 2503 build 18623.20266 on Thursday last week and it's been better but still had CPU spike on 3 occasions.