# Unreal Engine is using 100% of my CPU **URL:** \ **Category:** Platform & Builds\ **Tags:** bugs, cpu-usage, unreal-engine, CPU, question\ **Created:** [October 15, 2014, 4:18am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159 "2014-10-15T04:18:25Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![alobf](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@alobf](https://forums.unrealengine.com/u/alobf)\ **Post date:** [October 15, 2014, 4:18am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/1 "2014-10-15T04:18:25Z")
Hello When I open the Unreal Engine Launcher it uses 30% of my CPU, and when I move the window around it goes up to 100%!!! When I open the editor it gets much worse, the CPU stays almost at 100% of usage even though I’m at the lowest graphics quality My computer specs are: Toshiba Qosmio X70-A Intel Core i7-4700 MQ COU @2.40GHz 2.40GHz (8 cores) 32gb of RAM Windows 8.1 64-bit Intel HD Graphics 4600 NVIDIA GeForce GTX 770M UE4 is installed in the C drive which is a SSD Zip files with Screenshots thank you! ---
**Author:** ![Jonathan\_Dorman\_1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Jonathan\_Dorman\_1](https://forums.unrealengine.com/u/Jonathan_Dorman_1)\ **Post date:** [October 15, 2014, 3:01pm UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/2 "2014-10-15T15:01:24Z")
Hey alobf, I’m investigating your issue. Can you send me your full dxdiag? ---
**Author:** ![Jonathan\_Dorman\_1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Jonathan\_Dorman\_1](https://forums.unrealengine.com/u/Jonathan_Dorman_1)\ **Post date:** [November 4, 2014, 5:01pm UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/3 "2014-11-04T17:01:51Z")
Hi alobf, We have not heard back from you in a few days, so we are marking this post as Resolved for tracking purposes. If you are still experiencing the issue you reported, please respond to this message with additional information and we will offer further assistance. Thank you. ---
**Author:** ![demented\_hedgehog](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@demented\_hedgehog](https://forums.unrealengine.com/u/demented_hedgehog)\ **Post date:** [December 7, 2014, 2:07am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/4 "2014-12-07T02:07:10Z")
This problem still exists… there are duplicate reports of it: [Will the High CPU in unreal be fixed? - Debugging, Optimization, & Profiling - Epic Developer Community Forums](https://answers.unrealengine.com/questions/89958/will-the-high-cpu-in-unreal-be-fixed.html) and [Unnecessary consumption of CPU - Debugging, Optimization, & Profiling - Epic Developer Community Forums](https://answers.unrealengine.com/questions/72584/unnecessary-consumption-of-cpu.html) and [4.1.1 CPUs (annoyances), BUGS and Suggestions - Programming & Scripting - Epic Developer Community Forums](https://answers.unrealengine.com/questions/48621/411-cpus-annoyances-bugs-and-suggestions.html) and I’m seeing it as well (fwiw). My machine is a linux box and I’m seeing this problem on version 4.6. (my machine is underspeced sp? with 4Gb of ram… maybe it’s thrashing? (I’m off to get some more ram now… I’ll let you know if it makes a difference)). ---
**Author:** ![demented\_hedgehog](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@demented\_hedgehog](https://forums.unrealengine.com/u/demented_hedgehog)\ **Post date:** [December 7, 2014, 3:54am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/5 "2014-12-07T03:54:12Z")
Still seeing the problem with more RAM… uses 169% of my CPU doing nothing with a standard new project with starter content… I’ve not touched it at all. ---
**Author:** ![demented\_hedgehog](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@demented\_hedgehog](https://forums.unrealengine.com/u/demented_hedgehog)\ **Post date:** [December 7, 2014, 5:43am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/6 "2014-12-07T05:43:40Z")
Running the UE4Editor-Linux-Debug cmd I get a LOT of these [2014.12.07-05.34.39:407][260]LogRHI:Warning: [API][Performance][Medium][131218] Program/shader state performance warning: Fragment Shader is going to be recompiled because the shader key based on GL state mismatches. I also get all sorts of weird display artifacts. Using: bolt:UnrealEngine$ lspci | grep VGA 01:00.0 VGA compatible controller: NVIDIA Corporation GK107 [GeForce GT 640] (rev a1) With the latest NVIDIA-Linux-x86\_64-343.22 proprietory graphics driver ---
**Author:** ![Jonathan\_Dorman\_1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Jonathan\_Dorman\_1](https://forums.unrealengine.com/u/Jonathan_Dorman_1)\ **Post date:** [December 15, 2014, 8:29pm UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/7 "2014-12-15T20:29:49Z")
Hey demented\_hedgehog, Sorry for the wait. I’ve been looking into this issue and here’s what I’ve found: This is a Slate-related issue with Linux and while we’re working on making Slate less CPU-intensive, it’s a long-term plan. For the time being, you may need to use non-realtime viewports (clicking the Perspective button in the Viewport and setting it to one of the Orthographic viewports, for example). ---
**Author:** ![anonymous\_user\_89e0048d](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_89e0048d](https://forums.unrealengine.com/u/anonymous_user_89e0048d)\ **Post date:** [July 12, 2017, 2:00pm UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/8 "2017-07-12T14:00:10Z")
hi i have the same issue on my computer! my computer specs are windows 7 64-bit Intel i5 2310 2.9G memory 8G ddr3 1333 nvidia gtx 460 1G ---
**Author:** ![ste1199](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ste1199](https://forums.unrealengine.com/u/ste1199)\ **Post date:** [March 29, 2021, 10:50am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/9 "2021-03-29T10:50:59Z")
me to keep getting stuck on 39%. I have 20gb ram running at 1800mhz and my cpu amd fx 8350 8 core. graphics card titan x 12gb. I cant do anything can someone help I am supposed to be going to uni in September thanks ---
**Author:** ![KuroPhoenix7](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KuroPhoenix7](https://forums.unrealengine.com/u/KuroPhoenix7)\ **Post date:** [March 29, 2021, 11:16am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/10 "2021-03-29T11:16:59Z")
must be compiling shaders. It takes some time first time ---
**Author:** ![McSmithe](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@McSmithe](https://forums.unrealengine.com/u/McSmithe)\ **Post date:** [May 16, 2021, 7:04am UTC](https://forums.unrealengine.com/t/unreal-engine-is-using-100-of-my-cpu/296159/11 "2021-05-16T07:04:46Z")
I’m not sure if its related, but, I had a project that for some reason decided to open using only one core at full 100% while leaving the other 15 cores at 0% and it would then lag while navigating in the editor, I tried defining the amount of cores in the engine config (Program Files\Epic Games\UE\_4.26\Engine\Config\BaseEngine.ini) to no avail. Reinstalled the engine and it worked with all cores for a while and then again only one … lagging… full 100% while other 15 cores are 0%…FINALLY figured it out! It was the Razer Cortex game booster I didn’t even know was installed on my system that somehow was messing with my ue4 project CPU consumption. so I wanted to leave it here maybe it’ll help someone.