Science per minute is the top-level promise every downstream block must support.
Stable updates per second matter more than pretty entity density at megabase scale.
A fully compressed blue belt moves 2,700 items/min, so lanes need explicit ownership.
01 — What Makes a Megabase Blueprint Different?
Normal blueprints solve a local recipe. Factorio megabase blueprints solve a system contract: how many items enter per minute, how many items leave per minute, which belts must stay compressed, and how much UPS cost the design adds when copied fifty times.
The best 1000+ SPM modules are deliberately boring at the edges. Inputs land on named belts or train unloaders, outputs leave on measured lanes, and the middle of the build can be tuned without changing the rest of the factory. That is what lets a city block, science block, or rocket-control module scale without turning the entire base into one shared bottleneck.
Rule of thumb: if a blueprint cannot state SPM, input items/min, output items/min, power draw, and footprint, it is not ready to be a megabase module.
02 — Bus vs. City Block vs. Main Bus Megabase Designs
| Design | Scale | Best for | Megabase tradeoff |
|---|---|---|---|
| Starter bus | Up to ~150 SPM | Learning ratios and keeping mall/science inputs visible | The central belt spine becomes the bottleneck once plates, circuits, plastic, and low-density structures all compete for lane space. |
| Main bus megabase | 150–500 SPM | Players who want one-direction expansion without rebuilding every science block | It is easy to debug, but the bus gets extremely wide and creates long item travel times that add UPS pressure. |
| City block grid | 500–1000+ SPM | Train-fed modules, repeated science cells, and independent production blocks | The rail grid costs more up front, but each block gets clear input contracts, output targets, and expansion boundaries. |
03 — Real Megabase Blueprint Stats to Track
A full blue belt carries 45 items/sec, or 2,700 items/min. Use that number as the unit test for belt saturation: four blue belts need 10,800 items/min of genuine supply, not just enough machines to look impressive in editor mode.
| Blueprint target | Items/min | Power draw | Footprint | Use case |
|---|---|---|---|---|
| 64×64 production block | 10,800 items/min | ~99 MW | 64×64 tiles | Four blue belts of sustained output for repeatable city-block modules. |
| 1-4 train unload cell | 16,200 items/min | ~1.8 MW | 48×72 tiles | Six blue-belt lanes from balanced wagon buffers into one production input edge. |
| 1000 SPM science spine | 7,000 science/min | ~310 MW | 192×128 tiles | Seven science lanes with dedicated labs, beaconed assemblers, and isolated exports. |
| Rocket control + LDS cell | 2,700 items/min | ~146 MW | 96×96 tiles | One blue belt of late-game rocket intermediates without sharing circuit lanes. |
04 — UPS Efficiency, Belt Saturation, and Expansion Rules
Megabase optimization starts by removing ambiguity. Mixed belts, giant passive buffers, and undersized train unloaders can all hide a bad ratio until the base crosses a threshold and UPS drops. The blueprint should make starvation visible at the block edge before it becomes a factory-wide mystery.
Keep each module honest: one visible input contract, one output target, and no hidden shared buffer that masks starvation.
Prefer fewer long-distance belts and more local train handoffs once a build needs multiple blue belts of one item.
Reserve beacon, roboport, power pole, and train stacker space before the first copy-paste, not after throughput dips.
Measure at the block edge: input items/min, output items/min, belt compression, average power draw, and footprint tiles.
// complete megabase pack
Want the measured 1000+ SPM layouts instead of rebuilding the ratios by hand?
The Megabase Collection packages train blocks, late-game production cells, power layouts, and metrics sheets so every blueprint ships with throughput, belt saturation, power draw, and footprint numbers.
Open /buy/megabase→