4.17 Editor is slow in Arch Linux. How can I fix that?

The Editor’s performance in Arch Linux is very poor and I’m not sure what I could possibly do to improve it anymore.

It starts at around 30FPS and quickly dips to ~16FPS when interacting with the UI. The UI seems to be the main bottleneck, not the viewport. Setting the viewport to very minimum setting does not affect FPS. Running the game itself results in decent FPS.

I ran UE4Editor on W7 several months ago on this same computer and the FPS was significantly better so there must be something wrong with how it’s running on my Linux. I would very much appreciate help here since I really want to develop off of Linux and not Windows.
Edit: I ran the 4.17 Editor in W7 again and got 110FPS in the same default scene.

My specs:

  • OS: Arch Linux x86_64
  • Kernel: 4.12.8-2-ARCH
  • CPU: Intel i3-6100 (4) @ 3.700GHz
  • GPU: NVIDIA GeForce GTX 960
  • RAM: 16GB

Things I’ve tried:

Related to UE4 Editor itself:

  • built UE4Editor-Linux-Debug

  • Disabled tooltips

  • Ran with -DX12 switch

  • Ran with -opengl4 switch R R

  • Ran with -novsync switch

  • Ran with -useallavailablecores

  • Tried the r.GraphicsAdapter= -2

(There was never really any indication any of those CLI arguments did anything)

Related to my drivers:

  • I tried the nvidia package.
  • I tried the nvidia-full-beta-all package.
  • I have mesa installed.
  • I tried making specific rules for UE4 Editor for things like disabling vsync and antialiasing, just in case.
  • Set OpenGL to max performance on the quality vs performance slider in nvidia-settings.

Related to my Desktop Environment, KDE Plasma 5:

  • Every possible combination of
    compositor settings
  • Disabling compositing for UE4Editor
  • Killing plasmashell (no compositor,
    no index and no logging from plasma
    to possibly slow down the editor)
  • Used ksysguard to monitor CPU usage to make sure these isn’t something else hogging up CPU.

How are you measuring your FPS? in the viewport? Ofcourse it would drop when you are not in the viewport. Also you can do stat unit to see where the time is spent on the frame to help you identify the bottleneck, my guess would be your CPU. I have very similar setup but stronger CPU(i7) and 980ti and I do get 100+ FPS(on example project, if I add some demanding assets into the scene it drops :D)

test: block compositing, force, no

hope this helps.

i have no issue here on Manjaro KDE

I’m measuring FPS by enabling the appropriate UE4 Editor Preference in the Performance section, so no, I’m not measuring FPS in the viewport. Additionally the more UI panels I hide and the more of the screen the viewport is covering, the better my FPS, indicating that something about the Editor’s UI rendering and my Linux is wrong.

When using ksysguard to monitor things, UE4 ends up using all of my CPU. The thing is that in the same scene in W7 I get 120FPS. Albeit the UE4 version on my W7 is 4.13, so I’ll update and see if it starts acting as slowly as the Linux installation. Maybe it is an interaction of the newest version and my hardware, rather than an interaction between UE4 and my Arch. But it feels very Linux related and I don’t know what I’m doing wrong in setting this up.

Thank you for mentioning stat, I didn’t know about it. Though stat Unit seems like it measures just the game itself? A more useful measurement would include profiling the actual editor, not just the game, since it is the editor’s UI that is generating the high CPU usage. But I’ll give it a shot anyway!

Ah yes, I forgot to mention I tried this as well and it didn’t have any significant effect on FPS and editor lagginess. It fixes problems with the tooltips, but on the other hand leaving the tooltips enabled to begin with makes the editor slower even if they display correctly with compositing on. For example if tooltips are on and I move my mouse as fast as I can between buttons that trigger tooltips, the editor will dip to 0FPS and freeze until I stop doing this.

Okay, so what finally fixed it was not building the debug version. If you’re on Arch and you’re building the debug version to circumvent build errors - just don’t, try to fix the build errors and make a normal development build. The debug version has certain optimizations turned off among other things that can make UE4 very slow for you.

The editor is still less responsive than its Windows counterpart - it stutters a bit whenever an object is selected, which doesn’t happen on Windows - but I’m clocking in 90-110FPS now!

In my case I needed to upgrade my Mesa version

sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update & sudo apt-get upgrade

Hope that helps :slight_smile: