What is UE4 doing while idle?

I can’t help but to notice, at ALL TIMES, the Unreal Engine is running at least 15% of my CPU power. Even if I’m sitting on a screen just staring at a blueprint. What is it doing well idle? I see a little green icon of a cap and mortar blinking. Is that worth 15% CPU power? There are no materials running, the rest of the screen is doing nothing, I’m not even touching the machine, and it’s at 15%. What’s going on?

It’s not that engine will sit and do nothing. Even though you don’t do anything, engine still has to run update loop and render graphics (editor UI is quite expensive to render) which will consume cpu power. Also 15% cpu usage doesn’t mean much because it’s relative to maximum cpu performance.

Hey Max!

Just minimize the Epic Launcher AGAIN!

If it is on background minimezed and consuming CPU, just click on it and minimize again, it will stop running all the time

Good luck!

I think you miss the point, if there’s nothing going on, there is no need for it to refresh anything. That’s the systemic problem with the engine right now, it’s always doing something, even when that something is nothing.

Another good example of this is in in the material editor. If you open it, sometimes it forces you to recompile your materials. Or if you move a module around, but don’t actually change any of the pin layouts, it forces you to recompile the material. It’s ALOT of useless CPU activity, running the computer into the ground, to accomplish absolutely nothing at all.

It’s like when we use the “Tick”. We, as people who use the engine, know not to abuse the tick because it can run the computer up when nothing is happening. But the guys who make the very engine we use seem to be abusing the tick.

I’m talking about the Engine itself, not the Launcher. The Launcher seems to have it’s own 15% CPU waste, even in the background, but often it calms down on it’s own. I, personally, just shut it down as soon as the Editor has loaded, to avoid any problems.

Of course, yet again, it’s another item Epic has made that seems to run up the CPU, and at the same 15%, even when nothing is happening on the screen at all. I know I’m not the only one who’s noticed what a bear UE4 can be on the CPU.

I can appreciate that the engine is powerful, and therefore needs to do alot, but when nothing at all is being done, even for hours at a time, there’s no need for it to be battering the CPU.

Try disabling the realtime preview of the viewports and the content browser.


There is something going on with epic like the op says, What is it rendering why is it using gpu with no programs in use, i get after initial startup and load into library or shop has a cost but after that i should idle at normal temp, My pc i know what is being used, it’s all liquid cooled and should run at certain temps idle, i know when it’s rendering because my lights will change according to cpu/gpu use and everytime i use epic client, my heat use goes up like i’m rendering a still shot in daz3d, it’s clearly upto something but WHAT? bitcoin minning, are you using portion of my processing to mine coin or make transactions like bitcoin would. Why does it need to use so much GPU power idle, upto 45% percent at times, thats a fair amount on my i9 xcore 256gb mainboard with 12gb vram 2080ti nvidia card. why is it using so much power IDLE. windows doesn’t and it runs more processes.

Yeah i notice no one replies from Epic about this matter. What is the Platform rendering while Idle it’s using 45% gpu on something way after load in, none of my other platforms do this not even Steam. 45% is a lot of GPU power for nothing, you gonna pay my electric bill plus the use of my 2080ti gpu the card is worth $2500 and your adding working hours onto the card while idle and i would like to know the reason why. I could be playing a game with the amount of gpu used just by this platform while it’s idle at times. Are you baking shaders using my GPU when not in projects or Mining BITCOIN because nothing should be using that power while idle, windows doesn’t it runs more processes then your platform i don’t even get that heat while in editors unless i’m rendering or loading something in…

Hey @Cenobite69,

Hope you’re doing well!

In an attempt to help you with editor performance I’ve found a few resources that might help to make a difference.

  1. This forum thread is specifically giving suggestions on editor performance.
  2. And this is a bit of documentation that could also help out with any performance issues you’re having.

I truly hope these help and happy developing! :slight_smile: