CPU out of sync?

This might be absolutely normal. There are so many background OS services that take advantage of available CPU cycles… It would be worrying if you were observing unjustified spikes while the CPU is under considerable load.

But do have a look at the humble Taks Manager’s Processes list, ensure the window is on top, sort it by CPU utilisation and see if something suspicious spikes up - something that matches the frequency you observe in the graph. Make sure that the editor window has focus.

It could be something nasty and engine unrelated or as trivial as Epic Games Launcher being cpu hungry, as per usual :slight_smile: Or the mobo software repeatedly pinging unresponsive manufacturer’ servers, or Google chrome - as I type I can see it try to grab up to 20% of half the cores there are and close to a GB of RAM. Why, though?


This might be a strange question, but I don’t know how to describe it better. I noticed a strange fps drop in editor lately. Normally it works with nice and smooth 120fps but sometimes it drops to 90’ish. When I’m looking at unit graph it behaves strange - it hitches all the time:


I checked what is happening in Unreal Insights and it looks like this:

There are empty places in which nothing happens! I was trying to find any task that might cause all other threads to wait but without any luck.

And now - the fun part. After I reboot a computer everything goes back to normal!


I don’t think this is an Unreal issue, rather there is something really strange happening to my computer. I just want to ask if anyone here has any idea what can cause such strange behaviour?

I don’t know how to trigger this, sometimes it just starts to happening and won’t stop until I reboot a computer.

My specs:

  • Unreal Engine 4.25
  • Windows 10
  • AMD Ryzen 7 3800X

Thanks for any ideas and insights!

I did what You suggested and I’ve discovered that there were two devenv.exe processes running instead of one! I work on multiple projects (which some of them requires a legacy versions of Visual Studio) and when I closed one project the process for some reasons stucked and didn’t shut down properly. After killing it with process manager editor started working smoothly as It should. Thanks!

As @Everynone suggested - I checked for any suspicious processes running in the background and there were multiple devenv.exe processes running for any reason. Killing all unnecessary processes fixed the issue :slight_smile: