Why so bad perfomance at Godot TPS demo?

[anunknowperson]

Godot version:
3.2.3

OS/device including version:
GPU: Radeon RX 480 8GB
CPU: Intel Xeon (unknown)
Backend: GLES3

Issue description:
Why i have only 10 fps when i launch godot TPS demo with medium settings?
The scene isn't that complicated...

[Calinou]

Please report issues specific to the TPS demo on its repository, not here. That said, keep in mind that AMD's OpenGL Windows drivers offer worse performance than all competiting hardware and OSes (especially compared to NVIDIA).

The TPS demo's level is a single mesh, which prevents any frustum culling opportunities. On top of that, many areas not visible to the player are still modeled and textured. Once the level is split into several meshes, it should be much faster to render, especially if #41123 is merged.