Rubidium in All the Mods - Gravitas

Rubidium is a performance mod, and it's one of the first things I'd point a viewer to if their frame rate struggles in a big modpack. It's an unofficial fork of CaffeineMC's Sodium, made to run on Forge Mod Loader, and it carries all the features of classic Sodium. This pack ships Rubidium 0.5.6.^[1][2]

What it does for you

• A modern OpenGL rendering pipeline for chunks that uses multi-draw techniques. This cuts CPU overhead when rendering the world by about 90%, and you get steadier frame times even if your GPU can't keep up.^[1]
• More compact vertex data for rendered chunks, which cuts video memory and bandwidth requirements by almost 40%.^[1]
• Multi-threaded handling of nearby block updates, which reduces the lag spikes you get when chunks need updating. Chunk faces that aren't visible are also culled very early in rendering.^[1]
• Faster block entity, mob and item rendering, which helps when you've placed far too many chests in one room.^[1]
• Better memory handling, which reduces memory use and the lag spikes caused by garbage collection.^[1]
• Visual upgrades too: smooth lighting for fluids and other special blocks, plus smooth biome blending for blocks and fluids. Animated textures that aren't visible aren't updated.^[1]

Who it's for

Everyone, really. The biggest gains go to computers that aren't bottlenecked by the GPU or other components, but integrated GPUs can still see a modest speedup from the early culling of hidden chunk faces.^[1]

Unverified Where Rubidium fits in the pack's progression, including any link to the ATM Star path or to quests, isn't confirmed by the available sources.

Good news: there's nothing to craft first with Rubidium. It's an unofficial fork of CaffeineMC's Sodium made to work with Forge Mod Loader, and it contains all the features of classic Sodium. Its job is to make the game render faster, so the first steps are about knowing what it does for you.^[1]

What Rubidium does for you

• It uses a modern OpenGL rendering pipeline for chunk rendering with multi-draw techniques. The project page says this cuts CPU overhead when rendering the world by about 90%, and frame times become more stable even if your GPU can't keep up.^[1]
• Vertex data for rendered chunks is more compact, which cuts video memory and bandwidth requirements by almost 40%.^[1]
• Nearby block updates use multi-threading, which reduces the lag spikes you get when chunks need to be updated.^[1]
• Chunk faces that aren't visible or face away from the camera are culled very early, so the GPU doesn't process geometry it would throw away. Integrated GPUs benefit most.^[1]
• Block entity, mob and item rendering is faster, which helps when you place too many chests in one room.^[1]
• Smooth lighting now covers fluids and other special blocks, and smooth biome blending applies to blocks and fluids.^[1]
• Animated textures that aren't visible in the world don't get updated, which speeds up texture updating on most hardware, especially AMD cards.^[1]

Unverified I couldn't confirm any in-pack recipes, quests, items or pack-specific config changes for Rubidium, so this guide doesn't list any crafting steps or recommended settings. Check the in-game video settings screen yourself to see which options this pack gives you.

Rubidium doesn't have machines, multiblocks, power, fluids or item automation. It is a client-side rendering optimization mod, an unofficial fork of CaffeineMC's Sodium made to run on Forge Mod Loader. So the "mechanics" here are about how the game draws the world, not how you build or wire anything.^[1]

What it does under the hood

• Chunk rendering uses a modern OpenGL pipeline with multi-draw techniques. The project page says this cuts CPU overhead by about 90% when rendering the world, and gives you more stable frame times even if your GPU can't keep up.^[1]
• Vertex data for rendered chunks is more compact, which cuts video memory and bandwidth requirements by almost 40%.^[1]
• Nearby block updates use multi-threading, which reduces the lag spikes you get when chunks need to be updated.^[1]
• Chunk faces that aren't visible or face away from the camera are culled very early. That saves the GPU from processing geometry it would throw away anyway, which helps most on integrated GPUs.^[1]
• Chunk loading and block rendering are optimized, and so are vertex building and matrix transformations. That speeds up block entity, mob and item rendering, which helps when you have a lot of chests in one room.^[1]
• Memory management and object allocation are improved, which reduces memory use and the lag spikes caused by garbage collector activity.^[1]
• Animated textures that aren't visible in the world are not updated. This speeds up texture updating on most hardware, especially AMD cards.^[1]

Visual changes

Rubidium also fixes a number of graphical issues with smooth lighting, and it adds smooth lighting for fluids and other special blocks. It also adds smooth biome blending for blocks and fluids, which looks better and costs less performance.^[1]

Unverified The pack doesn't ship config files for Rubidium, and I found no in-pack tooltips, recipes or quests for it. I can't confirm any pack-specific settings or changes, so treat the figures above as the mod's own claims, not measured results in this pack.

All the Mods - Gravitas 4.0 ships Rubidium 0.5.6. The mod has been in the pack since Gravitas 1.1 or earlier, so it's a long-standing part of the modpack.^[2]

Rubidium 0.5.6

• Fixed chunk rendering with Immersive Engineering.^[3]
• Parity with Forge on rendering block sides.^[3]
• Fixed a crash when disabling the fast_biome_colors option.^[3]

Rubidium 0.5.4

• Fixed an ArrayIndexOutOfBoundsException, some memory leaks and underwater lightning.^[4]
• Corrected smooth lighting, which fixed a bug with the AE2 Drive and GregTech machines.^[4]
• Added compatibility with BetterLoadingScreen, and added a minVersion property.^[4]
• The mod is now ignored on servers.^[4]
• Switched to GlStateManager instead of raw GL, which gives better mod compatibility.^[4]
• Added the Cauldron to blended blocks.^[4]

If you're curious about what happened between these two releases, or in the pack's own changelogs, I don't have that information here. No pack changelog entries for this mod were available.^[2]