4.14.3 Bad performance with multiple windows open

When I have multiple (2-3+) editor windows open, e.g. static mesh editor window, mat instance editor window, the whole editor slows to a crawl, below 10 fps. This occurs even when the editors are tabbed and not currently being rendered.

With a single editor window open performance is ok.

This has started happening since 4.14.

[DxDiag][1]

Hey myertveho,

It is kinda hard to tell from your screenshot, but are you working on a single monitor screen?

I tried testing this on my end, but getting the windows to dock on a single screen display like your screenshot is showing. Either way, I tested both single and double screens and attempted to get the editor’s performance to slow down, but I was not seeing the drop in performance.

I might try testing on a weaker machine with less RAM to see if that reproduces the issue, but I will return once my testing has completed.

Thanks,

This is how it looks like with multiple windows, the performance is cut in a very linear fashion

  1. windows: 60fps | 16.7ms
  2. windows: 30fps | 33.3ms
  3. windows: 20fps | 50.0ms
  4. windows: 15fps | 66.7ms

  • it does not seem to matter how many monitors are involved
  • it does not seem to matter which window is in focus
  • this also affects the PIE mode
  • the editor’s ‘Use Less CPU when in Background’ setting does not affect this behaviour

tested on:
3570k @ 4GHz, 16GB, 7970 3GB, Win10 64b

Hey guys,

Thanks for taking the time to elaborate and provide some extra information. We were able to reproduce this internally and have entered a bug report for the issue. You can track the issue by clicking the link below.

UE-41678

Let me know if you have further questions or need additional assistance.

Cheers,

This has been happening forever, I can’t believe there wasn’t a ticket for it yet :slight_smile:

Thanks Andrew,

Sorry I didn’t get back to you earlier, these emails were going to spam.

I am also experiencing this exact issue

same for me
windows/linux 4.15.1

Please fix it!

Doesn’t this happen because the visualization of the blueprints? That’s been my assumption. All the nice orange wires lighting up to show you in real time what’s firing off has got to take its toll.

It happened with all window types, not only BP
I think problem is in UE interface toolkit, or in nvidia drivers, or windows/linux compositors.

i found solution here

Try link behind
But dx12 make ue unstable

Hi, i encountered similar probs. Is this still an open issue?

I have been working with 3 or 4 monitors for a very long time and just recently windows 10 updated (not sure if this was the cause or not) when this started happening. It drops below 10fps and unreal becomes unusable, the interface lags really badly.

If I type stat gpu in the editor it says Slate UI is taking anything between 20-200ms but as soon as I close all the extra windows and just have the main window it drops to 0.6ms.

I understand there is going to be some performance impact having more than one window open but it shouldn’t be this huge and never used to be a problem.

I’ve tried everything to fix this (including -DX12) but nothing helps, did anyone here solve the issue? It’s going to affect my productivity massively if I can’t fix it :frowning:

any update? this is simply unacceptable (using 4.18)

I’d like to pile on and say that this is still a huge issue in 4.21.

Just thought I’d come back and say I fixed this by uninstalling Geforce Experience. It seems the screen capture was causing it, it might also fix if you just disable that without uninstalling the whole thing.

I can’t believe this productivity breaking bug been in backlog for 4 years now…