Sudden drop in fps after 4096px width of the window

[Karmo]

I tried 0ad on 5120x1440 monitor and saw unplayable < 5 fps. Since the same computer can run it with > 300 fps with 1920x1200 resolution using same maximum quality settings I started to investigate how there is so massive difference in fps between these two resolutions. I run it in window mode and started expanding the window. Around 4050x??? I still got very smooth 120 fps experience. Buf if I rezied width of the window a bit more to about 4100px then fps dropped suddenly from 120 to around 5. I wrote ??? as height since it doesn't matter if window has 1440px or 300px height. Problem seems to be related to single dimension not total pixels. I cannot say what is the exact point when the fps drops but looks like it's 4096.

I can play other games such as CSGO, Dirt Rally 2.0 etc without lag using 5120x1440 resolution.

GPU: Nvidia 3050Ti Mobile (515.48.07 driver)
CPU: Intel i7 11800H
OS: Manjaro Linux (5.15.48 kernel)
WM: KDE Plasma (5.24.5)

Edited June 22, 2022 by Karmo

[Stan`]

Hey,

Sorry you are experiencing such troubles. Does it happen with the release or the experimental version of the game ?

Could you try switching off prefer GLSL to see if it makes a difference ? Same with postprocessing (In the game options)

We don't have any restriction for window size so it's not that.

Not sure which backend CSGo and Dirt Rally use. Vulkan? Or opengl 4+ ?

We're stuck at OpenGL2.1 so your GPU might be emulating some old stuff causing the lag (and or triggering a driver bug)

[Karmo]

Hi Stan,

I have a25b-4 version of the game from official Manjaro repositories.

I played with graphics settings and found out that it's very high shadow settings that kills fps after 4096px window width. Switching off GLSL or postprocessing didn't make game playable when shadows were very high. If I use just high shadows then I have over 100 fps with 5120x1440 but when switching to very high it decreases fps at least 20 times.

Just before the slowdown GPU memory usage and GPU utilization are around 30-40% and PCIe bandwidth around 20%. When I resize window over the limit then these numbers are 40%, 100%, 95%.