Linux. Can't disable triple buffering. High GPU, CPU load.

Kubuntu 23.04.
X11
AMD Ryzen 5 3600
Radeon RX580 8GB
RAM 16GB
75hz monitor
All renderers.
Lowest settings, 1920x1080, vsync off.
Fresh game install with game folder deletion before installation.
Steam client, Proton default compatibility.

Impossible to turn off triple buffering, drop-down list always sticks to Enabled.
100 fps in Karui shores, while on windows10 it's 150, before difference was maybe 20 fps, it was fine, now sometimes it's almost twice lower.
CPU 4ms (on windows 2ms, on linux before also 2ms)
GPU 9ms (on windows around twice less, on linux before also twice less)
VRAM usage only 1GB while RAM around 8-9GB, do not remember how it was before, I feel like VRAM usage was hight but not sure.
On maps without any pack size fps drops to 60 on windows and below 60 on linux.
On windows it's not really noticeable even if fps goes a bit lower than 75fps but on linux it's like constant stuttering, feeling like it's 30fps or less, while graph shows 100fps, with vsync it smooth but once it hits 74fps - stuttering.
Dynamic resolution does not work I believe, also about year or two ago it was possible to manually set dynamic resolution to 75fps in production_config.ini but later this possibility was removed and it's bad.
To play with stable 75fps with vsync I need to run 1280x720 constantly now.
Anything lower makes me dizzy, motion sickness is real.
(do not look at net latency, I accidentally logged on to Texas)



Update. With multithreading off there is no stuttering even tho CPU load is even bigger (15ms latency) and fps goes to 40 sometimes. Fps is low but it relatively smooth.

Update2. multithreading off results in "device lost" error after several minutes


Update3. Performance issues was caused by picom compositor effects (my fault) but it is still worse than before and latency is still few ms higher than before. No effect on most graphical options change still in place. Also I did not notice it earlier due to poor performance, but lighting effects and shadows are missing.

Linux is not officially supported. If the game is fine in windows and not ok in linux, with exactly the same hardware, then probably the driver or emulation layer of linux has problem, which i don't think GGG will offer support to unspported OS

"

neohongkong wrote:

Linux is not officially supported

They have Steamdeck which runs on SteamOS, which based on Debian with KDE which is basically Kubuntu. While Kubuntu is not officially supported it absolutely may have same core problem. If not - then it is what it is, but it's not for us to decide.

"

neohongkong wrote:

then probably the driver or emulation layer of linux has problem

It's same compatibility layer as on Steamdeck - Proton. Driver is the same as it was before update which caused problems for the whole player-base.

Update. With multithreading off there is no stuttering even tho CPU load is even bigger (15ms latency) and fps goes to 40 sometimes. Fps is low but it relatively smooth.

Update2. multithreading off results in "device lost" error after several minutes

Mesa (the open-source 3D library that the majority of Linux distros uses), has an override to enforce a minimum amount of buffers to 3, disabling double-buffering support:
https://cgit.freedesktop.org/mesa/mesa/tree/src/util/00-mesa-defaults.conf#n895, ie. this is not a Path of Exile issue.

You can work around this by making your own .drirc (which should take precedence over your distro defaults), or by setting the environment variable vk_x11_override_min_image_count to 2

For Steam users, that'd be setting the following as launch options:

vk_x11_override_min_image_count=2 %command%

Ultimately, there should be a feature request submitted to Mesa removing these lines, now that Path of Exile supports both double- and triple buffering.

"

gonXed wrote:

Mesa (the open-source 3D library that the majority of Linux distros uses), has an override to enforce a minimum amount of buffers to 3, disabling double-buffering support:
https://cgit.freedesktop.org/mesa/mesa/tree/src/util/00-mesa-defaults.conf#n895, ie. this is not a Path of Exile issue.

You can work around this by making your own .drirc (which should take precedence over your distro defaults), or by setting the environment variable vk_x11_override_min_image_count to 2

For Steam users, that'd be setting the following as launch options:

vk_x11_override_min_image_count=2 %command%

Ultimately, there should be a feature request submitted to Mesa removing these lines, now that Path of Exile supports both double- and triple buffering.

Thank you, very useful.

Offtop.
Maybe you also know why Steam launches PathOfExileSteam.exe instead of PathOfExile_x64Steam.exe? And does a way to fix it exist? or maybe it's intended?

UPD command and .drirc does not work. It's client problem I assume, because I used .drirc before they fixed backbuffer error and I was able to switch between double and triple buffering.

Latest patch did nothing on my config but deleting mesa driver cache helped to gain fps stability so stuttering is gone I guess but it's still a bit worse than was before.
Need further testing coz now i'm in process of shader compiling.

Everything else is still true.

Also GE-Proton seems to be adding few fps too.

Update3. Performance issues was caused by picom compositor effects (my fault) but it is still worse than before and latency is still few ms higher than before. No effect on most graphical options change still in place. Also I did not notice it earlier due to poor performance, but lighting effects and shadows are missing.