It seems that upon running UE4, even if the scene has “Realtime” turned off, I still see approximately 15% CPU usage on my Windows Task Manager.
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Are there any other settings/options that I could turn-off so that Unreal Engine would use less CPU processing when left idle?
Is this by-nature, due to it being a game engine?
UE4 4.10.2
Win 10
P.S.
These recent threads are probably semi-related: (although it is mainly for the Launcher)
That seems like a reasonable amount of usage, if the engine needed it then it would use a lot more than that
Doesn’t seem natural to me, however, I do have same high CPU usage as soon as I double click UE4 editor. I find UE4 to be generally more resource intensive.
Here is the Cryengine woodland level.
Thanks for the info regarding CryEngine. Does it also have an option to turn off “Realtime” mode? Or as soon as you change focus to another app, it stops using CPU cycles?
This somewhat cements the fact that game engines really does function differently… my concern mainly stems from having mostly used DCC apps.
I experimented on opening majority of my apps and left them on the background (minimized) to see if they are using my CPU. Here are the results:
&stc=1Notice that all of which seems to not be using my CPU when minimized, except for Photoshop, which exhibits a small tolerable amount.
Here are details on the running apps:
Adobe Photoshop CC 2015 - I have “all-layer-types.psd” opened, this file can be found with the installation.
Houdini Indie (15.0.393) - I simmed a shelf wave tank up to 10 frames, and left it at frame 10.
**Inkscape **- I have the “tango_icons.svg” opened, this file can also be found inside the installation folder.
**Krita **- I opened the template “web_design.kra”
**LibreOffice **- I opened a 2 page document
**Maya LT **- I opened a scene with geometry in it.
**Nuke PLE **- There does not seem to be any default sample files that come with the installation, so I just did a simple comp out of random images.
**Plant Factory **- I loaded the default bamboo scene, then drew a bunch of trunks.
Vue Complete 2015 - I have a default terrain scene opened.
World Machine - I opened the “Sweet Canyon Mesas” sample, pressed build, the left it at 3D view.
I also just noticed that the EpicGamesLauncher, when minimized would not use the CPU, which is great.
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And again, as can also be seen above, even when minimized, Unreal Editor is using around 14%.
I’m really hoping that there is something that I could turn off so that it wouldn’t use up CPU whenever it’s in the background 
Saving processor usage will really favor battery life of laptops and tablets when not plugged in.
This is still unacceptable for a background task, and definitely unacceptable for a background task that is idling.
Plus, the OpenGL buffer is also being refreshed at least three times per second while in the background, with absolutely no changes being made to the screen.
Other apps and game engines don’t do this. Here’s Unity and Unreal both running in the background, DOING ABSOLUTELY NOTHING. Between the Epic Games launcher (also doing nothing) and Unreal, often 20% of my CPU time is being wasted.
This cuts down on battery life and reduces the peak efficiency of other foreground processes. If I need to bake textures for my actors, I have to kill Unreal or the bake has to compete for CPU time.
-Chilton
This does not add up
Win10 64b + 3570k @ 4GHz, 16GB, SSD. I have a tendency to peek at the performance monitor ever so often and can confirm these are pretty accurate and persistent readings. Another thing I never understood is people complaining about the launcher, for me it always sits at 0 - 0.1% CPU time and uses around 200MB RAM. Even when open and playing flashy Fortnite video, it eats up to 5% of CPU time and a wee bit more RAM.
I believe this is a *very *acceptable behaviour. Yeah, the editor is RAM hungry, but that’s great, actually - apart from video editing something is finally taking advantage of the 12GB+ RAM I have.
Chrome is such an offender when compared to this.
I understand this is not really helpful for someone whose experience is totally different. By providing the data I’m merely suggesting that it’s not the editor that might be here to blame. I also find the argument about battery life moot. Is development ‘on the go’ really a sensible thing to do?
I know on the Mac version it’s been like this since the start. But it’s common to see this exact behavior in Windows apps that have been ported to the Mac.
They’re constantly redrawing the screen even when nothing has changed, among other things.
No idea why it’s like that on Windows though, for some users and not others. On my Windows laptop, it hovers at 1.2% in the background, which is wildly different than on my Mac.
Just to confirm, on the latest UE4 versions that I’ve used (4.15 up to 4.17) the processor usage has improved quite a lot.
When idle, minimized or in the background, I also see about the same amount (1.0%~1.5%) of usage on my end.
Using UE4 on Windows 10
There is an option in Editor Preferences->performance tab that reduces CPU usage when Unreal Editor is in background.
Awesome! I just checked, it seems to be turned on by default on 4.17.
Not completely related:
I have the same issue even in 4.17 with “Use Less CPU when in background” enabled in project with houdini plugin and don’t have it in project without said plugin. Probably have to bug SideFX about it too.
That’s strange. I have enabled option “Use Less CPU When in Background”, however Editor still consumes 100% of 1 CPU core 
