SpaceChem Bench: Sleepless on Sernimir IV

production_tutorial_3 Easy Multi-reactor production Multi-reactor Sernimir IV · SpaceChem Bench report →

Inputs: α Hydrogen (H), β Oxygen (O), γ Carbon (C). Output: ψ Formaldehyde (CH2O) ×10. Features: Max reactors: 2.

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 10 minutes to build a working solution and keep optimizing it, without seeing the community archive. 7 of 16 models solved it. No model found a new Pareto-frontier point beyond the frozen community archive.

7 / 16models solved it

811best LLM cycles (805 community)

0new frontier points

Records

Score	Community best	Best LLM	Model
Cycles	805	811	GPT-6 Astra · +1%
Reactors	2	2	Fable 5.1 Ties record
Symbols	21	21	Gemini 4 Argon Ties record

Community records from the community archive when we froze it on October 18, 2026. A point counts only after fresh-game replay and SChem’s precognition check.

Pareto frontier

Pareto explorer

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Community archiveModel frontier pointNew frontier point

Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Community archiveModel frontier pointNew frontier pointReactors are not shown; lower is better on both axes.

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Every model

Model	Solved	Best cycles	Best reactors	Best symbols	New frontier points
01GPT-6 Astra	Yes	811	2	24	—
02Opus 5.5	Yes	812	2	29	—
03Gemini 4 Argon	Yes	842	2	21	—
04Sonnet 5.5	Yes	916	2	52	—
05GPT-6.1 Sol	Yes	1,151	2	40	—
06Fable 5.1	Yes	1,252	2	51	—
07Gemini 3.8 Flash	Yes	1,452	2	47	—
08DeepSeek V4.1 Flash	No	—	—	—	—
09GLM-5.3	No	—	—	—	—
10GPT-6 Luna	No	—	—	—	—
11Grok 4.7	No	—	—	—	—
12Haiku 5.5	No	—	—	—	—
13Kimi K3.1 Pro	No	—	—	—	—
14MiMo-V2.6-Pro	No	—	—	—	—
15Muse Spark 1.3	No	—	—	—	—
16Muse Wonder 1.0	No	—	—	—	—

Best scores can come from different solutions. New frontier points are not matched or beaten on all three scores by any community solution.

Best model solutions

These solutions are in SpaceChem Community Edition export format and released under the MIT License. All of this puzzle’s model solutions are on GitHub and Hugging Face.

GPT-6 Astra Fewest cyclesFewest reactors

811 cycles · 2 reactors · 25 symbolsproduction_tutorial_3.811-2-25.txt on GitHub

Layout (Reactor 1 of 2)

Running in the game

GPT-6 Astra solution running on production_tutorial_3 in SpaceChem

SpaceChem Community Edition export (production_tutorial_3.811-2-25.txt)

SOLUTION:Sleepless on Sernimir IV,Player,0-0-0
COMPONENT:'drag-starter-reactor',12,13,''
MEMBER:'instr-start',180,0,128,1,0,0,0
MEMBER:'instr-start',180,0,32,3,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,2,4,0,0
MEMBER:'feature-bonder',-1,0,1,2,5,0,0
MEMBER:'instr-bond',-1,0,128,0,0,0,0
MEMBER:'instr-arrow',90,0,16,1,1,0,0
MEMBER:'instr-arrow',0,0,16,1,4,0,0
MEMBER:'instr-arrow',180,0,16,7,1,0,0
MEMBER:'instr-arrow',-90,0,16,7,4,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-input',-1,1,32,1,2,0,0
MEMBER:'instr-input',-1,0,32,2,1,0,0
MEMBER:'instr-rotate',-1,0,32,3,4,0,0
MEMBER:'instr-output',-1,1,32,7,3,0,0
MEMBER:'instr-grab',-1,2,32,7,4,0,0
PIPE:0,4,1
PIPE:1,4,2
PIPE:1,5,2
PIPE:1,5,1
PIPE:1,5,0
PIPE:1,5,-1
PIPE:1,5,-2
PIPE:1,5,-3
COMPONENT:'drag-starter-reactor',18,8,''
MEMBER:'instr-start',180,0,128,1,0,0,0
MEMBER:'instr-start',180,0,32,2,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,2,0,0
MEMBER:'feature-bonder',-1,0,1,2,1,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'instr-bond',-1,0,128,0,0,0,0
MEMBER:'instr-arrow',0,0,16,0,2,0,0
MEMBER:'instr-arrow',-90,0,16,0,4,0,0
MEMBER:'instr-arrow',0,0,16,2,1,0,0
MEMBER:'instr-arrow',-90,0,16,2,2,0,0
MEMBER:'instr-arrow',90,0,16,6,1,0,0
MEMBER:'instr-arrow',180,0,16,6,4,0,0
MEMBER:'instr-input',-1,0,32,0,3,0,0
MEMBER:'instr-grab',-1,1,32,0,4,0,0
MEMBER:'instr-input',-1,1,32,1,4,0,0
MEMBER:'instr-input',-1,0,32,2,2,0,0
MEMBER:'instr-rotate',-1,0,32,4,1,0,0
MEMBER:'instr-grab',-1,2,32,6,1,0,0
MEMBER:'instr-output',-1,0,32,6,2,0,0
PIPE:0,4,1
PIPE:1,4,2
COMPONENT:'drag-silo-input',5,9,''
PIPE:0,5,2
PIPE:0,6,2
PIPE:0,6,3
PIPE:0,6,4
PIPE:0,6,5
COMPONENT:'drag-silo-input',6,16,''
PIPE:0,5,2
PIPE:0,5,1
PIPE:0,5,0
PIPE:0,5,-1
COMPONENT:'drag-silo-input',4,2,''
PIPE:0,5,2
PIPE:0,6,2
PIPE:0,7,2
PIPE:0,8,2
PIPE:0,9,2
PIPE:0,9,3
PIPE:0,9,4
PIPE:0,10,4
PIPE:0,10,5
PIPE:0,11,5
PIPE:0,12,5
PIPE:0,13,5
PIPE:0,13,6
PIPE:0,13,7

Gemini 4 Argon Fewest symbols

842 cycles · 2 reactors · 21 symbolsproduction_tutorial_3.842-2-21.txt on GitHub

Layout (Reactor 1 of 2)

Running in the game

Gemini 4 Argon solution running on production_tutorial_3 in SpaceChem

SpaceChem Community Edition export (production_tutorial_3.842-2-21.txt)

SOLUTION:Sleepless on Sernimir IV,Player,0-0-0
COMPONENT:'drag-starter-reactor',12,12,''
MEMBER:'instr-start',180,0,128,4,1,0,0
MEMBER:'instr-start',0,0,32,8,7,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'feature-bonder',-1,0,1,2,7,0,0
MEMBER:'instr-arrow',90,0,64,1,1,0,0
MEMBER:'instr-arrow',0,0,64,1,4,0,0
MEMBER:'instr-arrow',180,0,64,7,1,0,0
MEMBER:'instr-arrow',-90,0,64,7,4,0,0
MEMBER:'instr-grab',-1,0,128,1,1,0,0
MEMBER:'instr-bond',-1,0,128,1,4,0,0
MEMBER:'instr-input',-1,1,128,2,1,0,0
MEMBER:'instr-input',-1,0,128,3,1,0,0
MEMBER:'instr-output',-1,0,128,6,1,0,0
MEMBER:'instr-grab',-1,0,128,7,1,0,0
PIPE:0,4,1
PIPE:0,4,0
PIPE:0,4,-1
PIPE:0,4,-2
PIPE:1,4,2
COMPONENT:'drag-starter-reactor',17,8,''
MEMBER:'instr-start',180,0,128,4,5,0,0
MEMBER:'instr-start',0,0,32,8,7,0,0
MEMBER:'feature-bonder',-1,0,1,1,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,2,0,0
MEMBER:'feature-bonder',-1,0,1,2,1,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'instr-arrow',0,0,64,1,1,0,0
MEMBER:'instr-arrow',-90,0,64,1,5,0,0
MEMBER:'instr-arrow',90,0,64,7,1,0,0
MEMBER:'instr-arrow',180,0,64,7,5,0,0
MEMBER:'instr-grab',-1,0,128,1,5,0,0
MEMBER:'instr-input',-1,0,128,2,1,0,0
MEMBER:'instr-input',-1,0,128,2,5,0,0
MEMBER:'instr-input',-1,1,128,3,5,0,0
MEMBER:'instr-grab',-1,0,128,7,1,0,0
MEMBER:'instr-output',-1,0,128,7,2,0,0
MEMBER:'instr-bond',-1,0,32,9,7,0,0
PIPE:0,4,1
PIPE:0,5,1
PIPE:1,4,2
COMPONENT:'drag-silo-input',5,9,''
PIPE:0,5,2
PIPE:0,5,3
PIPE:0,5,4
PIPE:0,5,5
PIPE:0,6,5
COMPONENT:'drag-silo-input',6,16,''
PIPE:0,5,2
PIPE:0,5,1
PIPE:0,5,0
PIPE:0,5,-1
PIPE:0,4,-1
PIPE:0,3,-1
PIPE:0,3,-2
PIPE:0,2,-2
PIPE:0,1,-2
PIPE:0,0,-2
PIPE:0,-1,-2
PIPE:0,-2,-2
PIPE:0,-2,-3
PIPE:0,-2,-4
PIPE:0,-2,-5
PIPE:0,-2,-6
PIPE:0,-2,-7
PIPE:0,-2,-8
PIPE:0,-1,-8
PIPE:0,0,-8
PIPE:0,1,-8
PIPE:0,2,-8
PIPE:0,3,-8
PIPE:0,4,-8
PIPE:0,5,-8
PIPE:0,5,-7
PIPE:0,5,-6
PIPE:0,5,-5
PIPE:0,5,-4
PIPE:0,5,-3
COMPONENT:'drag-silo-input',4,2,''
PIPE:0,5,2
PIPE:0,6,2
PIPE:0,7,2
PIPE:0,8,2
PIPE:0,9,2
PIPE:0,9,3
PIPE:0,9,4
PIPE:0,10,4
PIPE:0,10,5
PIPE:0,11,5
PIPE:0,12,5
PIPE:0,12,6
PIPE:0,12,7

Records

Pareto frontier

Pareto explorer

Search over time

The search over time

Every model

Best model solutions

GPT-6 Astra Fewest cyclesFewest reactors

Layout (Reactor 1 of 2)

Running in the game

Gemini 4 Argon Fewest symbols

Layout (Reactor 1 of 2)

Running in the game