Metroid Prime 2: Echoes (GC): Difference between revisions

This game suffers from severe stuttering during shader generation. Because of the differences between how the GameCube works compared to personal computers, whenever something uses the GameCube's GPU, Dolphin must generate a shader to emulate it on a PC GPU. Shader generation causes a slight emulation delay while it's being created, so Dolphin caches these shaders in its shadercache folder to help keep things smooth. Most games don't care about this and play fine, but with this game, the shaders are so massive that they cause a significant delay, which creates a hard stutter and desyncs the GPU and CPU threads. The game freaks out over this desync, creating a black bar at the bottom of the screen, which takes up 15% of the screen space and "squishes" the game in the remaining space. The black bar will remain there from then on whether stuttering continues or ceases. Going into new areas or showing new effects will cause the stutter and black bar, as well as going in and out of fullscreen and even taking a screenshot. Building up a shadercache of an area helps, but it will still stutter and desync if a new effect or region is loaded.

There are ways to prevent the black bar problem. Adding the line "GPUDeterminismMode=fake-completion" to the game's INI file under the [Core] section. This prevents the desync, while causing only a minor performance hit. It can also be worked around by playing in Single Core mode, but that causes a much larger performance hit. Unfortunately, none of these solutions address the underlying shader generation issues, and so stuttering will remain while using these workarounds. See {{issue|4336}} and {{issue|5185}}.