Breakneck Optimized is vanilla Minecraft, tuned. The best performance mods raise and steady your framerate, and voxy draws the world far past your render distance, even with shaders on: all included shader packs support it. On top of that you get support for OptiFine resource packs and the quality-of-life tweaks you'd install anyway. Every mod runs on your side only, so it works on any server and in singleplayer.
voxy turns the terrain beyond your render distance into lightweight LODs, so mountains, coastlines and villages stay in view for miles. It builds them from the chunks you explore, on servers too, and in singleplayer Voxy WorldGen generates the land around you, so the far view is there from the start.
Shaders need to support voxy to light that far terrain, so Breakneck keeps Sodium and Iris on versions where voxy and shaders work together. All eight included shader packs support it:
