If you have noticed unusual heat and fan noise from your computer after the screen has timed out and gone dark, Duplicati.GUI.TrayIcon may be the culprit. On Windows 11 it causes my laptop to get hot and loud when the computer is idle long enough for the screen to turn off. The heavy CPU usage occurs in dwm.exe but is caused by Duplicati.GUI.TrayIcon.
More details in github issue:
opened 08:49AM - 14 Apr 26 UTC
- [x] I have searched open and closed issues for duplicates.
- [x] I have se… arched the [forum](https://forum.duplicati.com) for related topics.
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## Environment info
- **Duplicati version**: duplicati-2.2.1.0_beta_2026-03-05-win-x64-gui
- **Operating system**: Windows 11 25H2
- **Backend**: OneDrive
## Description
The Duplicati.GUI.TrayIcon process causes heavy CPU usage in dwm.exe when screen is off. If my computer is idle long enough for the screen to turn off, then dwm.exe starts consuming a lot of CPU and the fan in my computer spins up. When screen is woken up and unlocked, then cpu usage returns to normal.
The heavy cpu usage is in the windows desktop window manager (dwm.exe), but it is caused by Duplicati.GUI.TrayIcon. If I shutdown Duplicati.GUI.TrayIcon, then the problem doesn't happen. If I start Duplicati.GUI.TrayIcon again, then the problem returns.
A similar issue has occurred in older Firefox versions, as well as other windows applications. Here is a relevant Firefox bug report that may be helpful:
https://bugzilla.mozilla.org/show_bug.cgi?id=1924932
The heavy CPU usage can be seen in the windows Resource Monitor tool. If you start the tool, then let the screen timeout, then look at the tool immediately after waking up the screen, you can see that the Average CPU for dwm.exe is high, then ramps down to normal.
## Steps to reproduce
1. Run Duplicati.GUI.TrayIcon.exe
2. Run Resource Monitor (can launch using win-R resmon)
3. Observe value in "Average CPU" column for dwm.exe, it's probably less than 1
4. Press ctrl-alt-del to lock screen
5. Wait for screen to timeout and turn off/dark
6. Wait another minute at least. On a laptop, you'll probably notice the fans ramping up.
7. Wake and unlock the screen
8. Quickly look at Average CPU value for dwm.exe. Note that it is much higher than before.
9. Observe that the CPU usage by dwm.exe decreases, and computer fans return to normal idle state.
10. Now shutdown Duplicati.GUI.TrayIcon.exe
11. Repeat steps 4-7 with the tray icon not running
12. Observe that dwm.exe cpu usage did not ramp up while the screen was off
- **Actual result**:
High idle CPU load while screen off
- **Expected result**:
Normal idle CPU load while screen off
## Screenshots
Idle CPU usage with screen on:
<img width="708" height="168" alt="Image" src="https://github.com/user-attachments/assets/e88029f1-5821-41cf-a4fe-986cc995ac6e" />
Idle CPU usage shortly after waking up screen:
<img width="708" height="168" alt="Image" src="https://github.com/user-attachments/assets/787029a1-72db-4695-8939-4644a213a3f2" />
## Workaround
My current solution is to stop using Duplicati.GUI.TrayIcon completely. Instead I'm running Duplicati as a service, and I just bookmarked the server url (http://127.0.0.1:8200/ngclient/) in my browser. This avoids the problem because the heavy cpu load is caused by the tray icon, not by the server.
One workaround is to simply not use the tray icon. You can disable automatic startup of Duplicati.GUI.TrayIcon if enabled, then run the server as a windows service.
To access the Duplicati Gui, you can bookmark the URL in a browser (http://127.0.0.1:8200/ngclient/ ). Note that for this to work, you will need to know the password for the server.