# Lots of CPU stalls, Render thread spikes

**URL:** <https://forums.unrealengine.com/t/lots-of-cpu-stalls-render-thread-spikes/387289>\
**Category:** Character & Animation\
**Tags:** UE4-15, UE4-11, unreal-engine, question\
**Created:** [March 8, 2017, 9:46am UTC](https://forums.unrealengine.com/t/lots-of-cpu-stalls-render-thread-spikes/387289 "2017-03-08T09:46:38Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Markus\_Maximus](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/markus_maximus/32/1069600_2.png) [@Markus\_Maximus](https://forums.unrealengine.com/u/Markus_Maximus)\
**Post date:** [March 25, 2017, 4:59pm UTC](https://forums.unrealengine.com/t/lots-of-cpu-stalls-render-thread-spikes/387289/2 "2017-03-25T16:59:46Z")

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The problem was found in **garbage collection**. The time between purging pending kill objects was set to 1 second for testing purposes and left out. For anyone else experiencing similar ‘hitches’ every few seconds, make sure that **‘Time Between Purging Pending Kill Objects’** is set to its default of 60 seconds in **Project Settings → Engine → Garbage Collection**.

Or better yet, disable GC if not needed to eliminate these hitches all together as specified in the following document:

> **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)**
>
> After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — ue4community.wiki! You will be able to find content from the official...

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