Smarter chunk invalidation for VulkanMod — because not every block change deserves a full cache bust.
Iodium is a client-side performance mod that optimizes how VulkanMod handles chunk section invalidation during block updates.
Every time a block changes, VulkanMod calls setSectionDirty on the affected chunk sections — which internally removes them from the render region cache and queues a rebuild. The problem? This happens every single time, even if that section was already queued for a rebuild three calls ago.
During an explosion, a piston sequence, or rapid mining, this can mean hundreds of redundant cache invalidations per frame — all doing the same work, all for nothing.
Iodium fixes this.
Iodium tracks which chunk sections have been marked dirty over a rolling 5-frame window. When a section is already in the dirty set, subsequent invalidation calls for that section are skipped entirely — no redundant cache busts, no wasted work.
Without Iodium:
Block A changes → setSectionDirty → cache invalidated ✓
Block B changes → setSectionDirty → cache invalidated (again) ✗ wasted
Block C changes → setSectionDirty → cache invalidated (again) ✗ wasted
Block D changes → setSectionDirty → cache invalidated (again) ✗ wasted
With Iodium:
Block A changes → setSectionDirty → cache invalidated ✓
Block B changes → already dirty → skipped ✓ saved
Block C changes → already dirty → skipped ✓ saved
Block D changes → already dirty → skipped ✓ savedAfter 5 frames the tracking resets, ensuring sections are always re-evaluated and nothing gets stuck.
| Scenario | Impact |
|---|---|
| 💥 TNT / Explosions | Very High — dozens of sections dirty at once |
| ⛏️ Rapid Mining or Building | High — continuous per-block invalidations |
| 🌊 Fluid Spread (water, lava) | High — wave-like section updates |
| 🔴 Redstone Chains | Medium — cascading block updates |
| 🌄 Normal Exploration | Low — but still reduces background noise |
| Mod | Status |
|---|---|
| ✅ VulkanMod | Required |
| ✅ Lithium | Compatible |
| ✅ Nvidium | Compatible |
| ❌ Sodium | Incompatible — use Plutonium244 instead of Iodium |
| ❌ Iris Shaders | Incompatible |
Using Sodium instead of VulkanMod? Check out Plutonium244 — the sibling mod built for the Sodium pipeline with subchunk-level dirty tracking.
Iodium into your mods folder| Minecraft | 26.1.2 |
| Fabric Loader | ≥ 0.19.3 |
| VulkanMod | Any version |
| Java | 25+ |
| Side | Client only |
Made by BlackGiack — also the author of Plutonium244, the Sodium equivalent of this mod.
Both mods share the same philosophy: don't do work that's already been done.
The name Iodium comes from Iodine (I, element 53) — because sometimes a small element makes all the difference.
