Unreal Editor High CPU Usage When Idle

How to fix it

Try these in order — the most common fix is first.

1. 1. Enable background throttling

   Copy steps
   1. Editor Preferences > General > Performance (older versions: Miscellaneous)
   2. Tick 'Use Less CPU when in Background'
   Did this fix it? Yes No

2. 2. Cap the frame rate

   1. Run t.MaxFPS 60 in the console, or set it in ConsoleVariables.ini
   Did this fix it? Yes No

3. 3. Disable realtime

   1. Viewport dropdown > untick Realtime, close unused viewports and panels
   Did this fix it? Yes No

4. 4. Test plugins

   1. Disable suspect plugins (Houdini was reported) and retest
   Did this fix it? Yes No

Symptoms

Unreal Editor uses a large share of CPU or GPU with nothing happening, fans spin up, or the laptop drains battery.

Why it happens

• Realtime viewport rendering continues while idle
• Throttling in background disabled or ineffective on some platforms
• Plugins that tick constantly
• Thumbnail and asset indexing work

This guide also covers

• unreal engine high cpu usage idle
• unreal editor fans loud
• unreal engine editor using too much cpu

The same problem in other apps

All slow, laggy or resource-hungry guides →

• Why Is Unity Editor So Slow (Unity)
• Blender Viewport Lag / Slow Viewport (Blender)

Other Unreal Engine errors

• Unreal Engine Fatal Error Crash
• Unreal Engine GPU Crashed or D3D Device Removed
• Unreal Engine Shaders Compiling Forever (Stuck at 45%)
• Unreal Engine Out of Video Memory Error
• Unreal Engine Project Won't Open After Upgrade
• Epic Games Launcher Stuck Installing Unreal Engine
• Unreal Engine Packaging Failed (Unknown Cook Failure)
• Unreal Engine Visual Studio C++ Build Errors