#Luanti version

Luanti 5.10.0-dev-debug (Linux)
Using LuaJIT 2.1.ROLLING
Built by GCC 14.2
Running on Linux/6.10.6 x86_64
BUILD_TYPE=Debug
RUN_IN_PLACE=1
USE_CURL=1
USE_GETTEXT=1
USE_SOUND=1
STATIC_SHAREDIR="."
STATIC_LOCALEDIR="locale"

#Irrlicht device

X11

#Operating system and version

GNU Guix System

#GPU model

Intel GMA 4500 MHD

#Active renderer

OpenGL 2.1

#Summary

Luanti is significantly slower with shaders enabled compared to no shaders when displaying exactly the same thing. This isn't a new issue: I get similar results with the same GPU on a different computer with Minetest 5.6.1 and Debian 12.

Without shaders (22 FPS): https://x0.at/bqPG.png With shaders (14 FPS): https://x0.at/4KUX.png

Effects that depend on shaders (post-processing, waving nodes, dynamic shadows) are all disabled.

#Steps to reproduce

1. Join a world with shaders enabled (make sure it's already generated since the mapgen can also slow things down)
2. Disable shaders and join exactly the same world