Use Less CPU Toggle Doesn't Save

I’m running into a slightly frustrating problem with the Use Less CPU when in Background toggle in the Editor Preferences.

During a time when working with VR in 5.0, I followed some guides that mentioned disabling when working with VR. But ever since then, if I re-toggle it, it goes back to being un-toggled, no matter the project, every time Unreal is restarted.

And it doesn’t seem to matter if I save it, reset the defaults, or even manually edit the .ini files. It always returns to un-toggled. And it seems to specifically be just this CPU feature. Others seem to save fine.

It’s not earth-shattering, but it is frustrating. This has persisted throughout every major version update to 5.3.

Has anyone else encountered this?

I have been having this exact same issue at home on my personal computer. Doesn’t happen on my work computer though, where I leave the setting enabled.

Every time I load the editor, I have to go into Editor preferences and Enable “Use Less CPU when in Background” because it never saves it on by default.

I have even tried “Set as Default”, but after restarting the editor, the setting is always disabled. “Reset to Defaults” will enable it though, since it was previously set as default. And you can see that “bThrottleCPUWhenNotForeground=True” is added to an .ini but doesn’t change anything on load.

Just like in your case, I’m only having this issue with the “bThrottleCPUWhenNotForeground” not being read or being overridden at some point on load. All of the other settings seem to read fine.

I wonder if there’s a plugin or previously deprecated feature that has been forcing this setting to override to disabled.

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I have the same issue in UE 5.3.2. It’s exactly as camelpouch described.

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I have also the very same issue. I tried everything:

  • Removed Unreal 5.3.2 and emptied everything in App Data/Local/UnrealEngine
  • Reinstalled Unreal 5.3.2 (in a different location now)
  • Removed the “Saved” folder of the project and the DefaultEditorSettings.ini and other possible config files.
  • I even started from a scratch in a different computer, fetched the project from git.
    The checkbox never stays on.

However, if I start any new project, it will have no issues on having it checked permanently.

So something in the project itself is not allowing this checkbox to be saved. The option works though so I have to remember each time. Considering how Unreal maxes out your GPU and CPU most of the time, it is a must for me to have on if I want my computer and electricity bill to take a break from time to time.

It seems to be fixed in 5.4.0. In a newly created 5.4.0 project, “Use Less CPU when in Background” is on by default, and it persists when the project is closed and open again.