Arcturus update: November 6, 2026 · GTNH 2.8.1 → 2.9.0 stable
What you need to know
- You do not need to rebuild every multiblock. Many old controllers still work as legacy machines in 2.9.0.
- Check farms and fuel production first. CropsNH changes growing conditions and replaces the old IC2 crop automation.
- Only convert a controller when you are ready to rebuild. You still need to build the new structure and reconnect its pipes and patterns. Deprecated controllers are scheduled for removal in the next major update; they are still available in 2.9.0. Compatibility and conversions.
Check these first
Start with the lines that keep your base running: steam, fuel, crop products and ore processing. The changes below apply to the new structures. Legacy controllers keep their own structure checks and machine logic.
| Machine | What changes | What to do |
|---|---|---|
| Ore Washing Plant / Industrial Chemical Bath | The legacy washer still runs washing and Chemical Bath recipes. New controllers split those jobs between two multiblocks. | If you use both functions, keep the legacy washer running. Split patterns and fluid feeds between the two machines when you rebuild. |
| Industrial Bending Machine / Industrial Forming Press | The legacy press still bends and forms. Each function now has its own multiblock. | One old controller converts to either a bender or a forming press. Running both lines needs two controllers and separate patterns. |
| Algae Farm | The legacy pond still works. The new farm needs EU, tiered glass and exactly one regular energy hatch. | Bring power to the site before rebuilding. If the algae feeds a fuel line, allow for the farm’s EU draw and test its output. |
| Industrial Arc Furnace | The new furnace uses electrodes and Normal/EBF/Ore modes. | Keep the old multiblock for now. After rebuilding, set up its electrodes, choose the mode and connect the molten outputs. |
| Industrial Cutting Factory | Sawblade material sets speed, parallels and EU discount in the new structure. | Size the line around your sawblade material, and reconnect its lubricant supply. |
| Industrial Coke Oven | The new oven grows in slices. Casing tier and slice count set parallels; coils reduce EU use. | The legacy oven still works. Choose the new size and coils for the volume you want to process. |
| Large Boilers | New bronze and steel boilers produce regular steam; titanium and tungstensteel variants produce superheated steam. | Legacy boilers can keep running. When rebuilding, provide enough water and a turbine suited to the steam type. |
| Mega Distillation Tower | The new tower has variable height, different output positions and Tower/Distillery modes. | Convert the controller in a LuV assembler. Allow room for the whole tower and connect each fraction to the correct output hatch. |
| Mega Oil Cracker | New casings and coil-based EU savings. Cracking fluid goes into the middle input; hydrocarbons go into a side input. | The legacy cracker remains available. Conversion needs a LuV assembler; reconnect steam/hydrogen and oil to their separate hatch positions. |
| Exothermic Hearth (Mega EBF) | Replaces Mega EBF. Parallels ramp up during continuous operation. | The legacy Mega EBF still works. Controller conversion needs a ZPM assembler; plan for the new coils, glass and gas connections. |
| Endothermic Fridge (Mega Vacuum Freezer) | Replaces Mega Vacuum Freezer. It gains speed while running; extra cooling is optional. | Keep using the legacy freezer until you are ready. Conversion needs a ZPM assembler. Connect coolant supplies before enabling enhanced cooling. |
| Fluid Shaper / Mass Solidifier | The old Fluid Shaper still works. Mass Solidifier assigns a ghost mold to each Solidifier Hatch. | Set the ghost mold in each Solidifier Hatch for the fluid fed into that hatch. |
Washing and Chemical Bath now have separate builds
Yoshy2002 · ya9yu / PCGMatt · LGPL-3.0+
If your legacy washer handles both jobs, leave it running until you are ready to replace it. Move Chemical Bath patterns to the new Industrial Chemical Bath; the new Ore Washing Plant cannot run them. Both structures.
CropsNH: farms need attention
- Migration converts IC2 crop blocks and stored seeds to CropsNH. Migration clamps their stats to the new range and resets growth progress. Conversion.
- Do not send an automatic breaker at a migration crop. It holds the original seed. Give it suitable soil, or right-click to retrieve the seed. Recovery.
- Check growing conditions and supplies: soil, water, fertilizer and Weed-EX. Harvest and process one batch, then adjust filters if the output items have changed.
- Old OC crop bots will no longer work. CropsNH does not provide the OpenComputers integration those scripts relied on. FAQ.
- Industrial Farm is the multiblock for CropsNH seeds. The new Extreme Industrial Greenhouse does not accept them. A saved greenhouse can keep its old structure, but seed compatibility is a separate issue. Industrial Farm, greenhouse.
AE2 and automation
- Request one item craft and one fluid craft, then try again after reloading the chunks. Watch P2P links, blocking cards, interface stock and where the fluids actually go.
- A red pattern slot can flag a pattern in the wrong type of interface. Hiding an interface from the terminal does not disconnect it. Interface changes.
- Tunnel Patterns are optional. They let several recipes share a group of inputs. Your existing patterns do not need rewriting. How they work.
Other changes worth a quick check
- Maceration Stack: T1 is unchanged; T2 has a new structure and higher speed. Details.
- Mixer, Wire Factory and Packager: pipe casing tier sets the speed of the new structures. An energy hatch upgrade alone will not tell you their throughput. Mixer.
- Mega Chemical Reactor: the new structure allows hatches anywhere on its casings. Glass tier limits energy hatch tier; lasers need UV glass or better. Construction.
- Other structure reworks: centrifuges, electrolyzer, extruder, sifter, turbines, Pyrolyse Oven and more are collected in GuideNH’s structure index. They do not all need an update-day rebuild.
- Recipes: if you make titanium tetrachloride from titanium dust, revisit the inputs and throughput; that route was nerfed. Endgame lines also need a look at Bioware SoC solder and NAC circuit patterns. Titanium, Bioware, NAC.
Before the update
- Let long crafting jobs finish and stock up on fuel, food and essential chemicals.
- Record controller modes, circuits and hatch positions for critical lines, plus the stats of your crops.
- Install the 2.9.0 stable client separately; keep your 2.8.1 instance and waypoints.
- Leave working multiblocks standing. Plan power, space and materials before converting controllers.
After the update
- Check power, water and steam loops before starting heavy machines.
- Run a familiar recipe in each critical machine. If it will not start, read the controller error before taking the structure apart.
- Inspect crops and stored seeds; test the full harvest and processing chain.
- Test ME item/fluid crafting and check quest/team progress.
If something breaks, include coordinates, the controller name, recipe and an error screenshot in your report.