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[2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sat Jun 21, 2025 5:32 am
by wavefront32
I just updated my system to KDE Plasma 6.4 and the rendering performance of Factorio using the Wayland backend has seriously degraded. The performance of the X11 backend appears to be the same as before.

I haven't attached a save file because you can reproduce in a brand new standard scenario game, or just from the main menu.
Operating System: Arch Linux
KDE Plasma Version: 6.4.0
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.15.3-2-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 32 × AMD Ryzen 9 9950X3D 16-Core Processor
Memory: 64 GiB of RAM (62.4 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 4090
Manufacturer: ASUS

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sat Jun 21, 2025 11:18 am
by Rseding91
That 100% sounds like a KDE Plasma developer issue given *we* didn't change anything and it got worse with their update.

However, I'll leave this for the linux guys to decide.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sat Jun 21, 2025 5:44 pm
by wavefront32
I agree it’s likely a KDE Plasma or SDL issue, but just in case it isn’t I also filed a bug here. Factorio is one of the few games that supports the Wayland SDL backend!

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sat Jun 21, 2025 9:49 pm
by orangep9
Same issue here with plasma 6.4 on arch. Has anyone made a report on the plasma side?

Edit: Also is there any way to debug what went wrong here easily? It seems like making a bug report that says "Factorio rendering performance is terrible on plasma 6.4 using wayland as the preferred video driver!" could use more details.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sat Jun 21, 2025 10:07 pm
by wavefront32
orangep9 wrote: Sat Jun 21, 2025 9:49 pm Same issue here with plasma 6.4 on arch. Has anyone made a report on the plasma side?

Edit: Also is there any way to debug what went wrong here easily? It seems like making a bug report that says "Factorio rendering performance is terrible on plasma 6.4 using wayland as the preferred video driver!" could use more details.

I plan to file a bug tonight. Just haven’t had the time yet.

I also haven’t had the time to setup profiling, but maybe I will if either the folks here or at KDE need more information.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sun Jun 22, 2025 3:55 am
by wavefront32

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Sun Jun 22, 2025 8:37 pm
by Jap2.0
Factorio is using software rendering (llvmpipe) instead of your GPU. If you're using the same version of Factorio as before the update, that seems like either a Plasma issue or a Mesa issue.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Tue Jun 24, 2025 5:42 am
by wavefront32
Jap2.0 wrote: Sun Jun 22, 2025 8:37 pm Factorio is using software rendering (llvmpipe) instead of your GPU. If you're using the same version of Factorio as before the update, that seems like either a Plasma issue or a Mesa issue.
I didn't even notice that line in the log. That certainly explains the slow rendering. Using the same version of Factorio. Since I'm using an Nvidia GPU, Mesa should not be very involved (beyond the vendor-neutral loader I think).

Still hoping to get time sooner to run a few more tests. I'd like to try a non-Steam version in particular with instrumentation and/or a debugger.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Tue Jun 24, 2025 8:01 pm
by Jap2.0
wavefront32 wrote: Tue Jun 24, 2025 5:42 am I didn't even notice that line in the log. That certainly explains the slow rendering. Using the same version of Factorio. Since I'm using an Nvidia GPU, Mesa should not be very involved (beyond the vendor-neutral loader I think).

Still hoping to get time sooner to run a few more tests. I'd like to try a non-Steam version in particular with instrumentation and/or a debugger.
Ah, sure. I have a habit of saying "Mesa" instead of "your graphics driver" when talking about Linux... I don't know if that gets updated at the same time as Plasma or not though.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Tue Jun 24, 2025 8:28 pm
by wavefront32
The issue appears to in fact only reproduce with the Steam version of the game. Even with the Steam overlay disabled, the llvmpipe OpenGL implementation gets picked. The same game version downloaded from the web site with the same config properly loads my GPU vendor (Nvidia)'s OpenGL driver.

I am currently in the Steam client beta channel. I will switch to stable and see if it reproduces.
Steam Beta Branch: Steam Beta Update
Steam Version: 1750726487
Steam Client Build Date: Mon, Jun 23 16:25 UTC -08:00
Steam Web Build Date: Mon, Jun 23 17:48 UTC -08:00
Steam API Version: SteamClient022

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Tue Jun 24, 2025 8:33 pm
by wavefront32
It does reproduce with the Steam client stable channel as well.
Steam Beta Branch: Stable Client
Steam Version: 1747701111
Steam Client Build Date: Mon, May 19 12:51 UTC -08:00
Steam Web Build Date: Mon, May 19 17:21 UTC -08:00
Steam API Version: SteamClient022

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Tue Jun 24, 2025 11:01 pm
by orangep9
Same thing here. Running the game on steam through gamescope also fixes the issue.

Re: [2.0.57] Dramatic Wayland rendering performance issue on KDE Plasma 6.4

Posted: Wed Jun 25, 2025 11:46 am
by wdimble
I updated to KDE Plasma 6.4.1 this morning, and the issue appears to have been fixed there.