Stuttering and low framerate after alt+tab [Linux]

[rauyran]

I can start the game and play normally at 60fps (acccording to the steam overlay). However if I switch away and return using alt+tab (or if I get a notification popup from my OS) then the framerate drops to 1. It may be a lot less since I can see the glow effects around empty building slots slowly pulsate as though it were redrawing every half a second or so.

It's completely unplayable and I have to restart which fixes the issue.

This has only started occurring since 1.29.1. Note that is has occurred in Stellaris for a long time so perhaps there is something similar between the two games.

I am on Linux using Gnome. I've attached system.log ans settings.txt

 

[AndrewT]

EU4 was updated to be 64bit in 1.29, but are you saying 1.29 was okay and this only happened since 1.29.1 ?

In Steam please click on Steam-Help-System Info, and paste everything there into a text file and attach that here.

 

[rauyran]

As far as I can tell this started in 1.29.1 but I didn't play 1.29 very much so I might not have triggered it.

System info attached.

 

[rauyran]

I found this issue which might be related. https://github.com/ValveSoftware/csgo-osx-linux/issues/1283

I checked the PCIe Bandwidth Utilization as suggested in that issue and found that it was 75-85% while the stutter was happening. It might be that I'm running out of GPU memory and the game or my OS is swapping textures.

After alt-tab

Spoiler

After closing EU4:

Spoiler

I tried to capture it while the game was running but I can't do that when running full screen. The problem does not seem to happen when running in a window even at 4k resolution but I can't play that way since it cuts off part of the game display.

 

[rauyran]

I think the problem is just that I had less than 2GB GPU memory available. I closed some things down until I had about 2.3GB free and now I can alt-tab freely. The memory usage rises close to my limit of 4GB but seems to be ok.

I'm happy that this is resolved for the moment.

I thought it was ok, but it's not. I managed to capture a screen shot of nvidia-settings while it was happening and you can see the GPU is working at about 98% but there is some free GPU memory and the PCIe Bandwidth looks ok.

Spoiler

 

[AndrewT]

I see, I don't think there's anything you or I can do about this. I suspect it's similar to the performance issues we're seeing on Macs (also openGL of course) and some Windows installations since 1.29, although it only happening after an alt-tab is unique I think.

Can I ask you please to post this in Bug reports, with all the stuff you've got together for this thread, so QA can look into it with the devs.

Sorry for that problem!

 

[grotaclas]

The problem does not seem to happen when running in a window even at 4k resolution but I can't play that way since it cuts off part of the game display.

As a workaround for the cut of of the game display, you can try to run in borderless fullscreen. Or you can change the window to a non-standard size by changing windowed_resolution in pdx_settings.txt. It should be in ~/.local/share/Paradox Interactive/Europa Universalis IV