GPT-5 Pro vs Ternary Bonsai 2 27B
Ternary Bonsai 2 27B costs 240.0x less per output token than GPT-5 Pro ($0.50 vs $120.00 per million). Updated October 22, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $120.00
- Coding
- No data
- Overall
- No data
- Output $/M
- $0.50
GPT-5 Pro or Ternary Bonsai 2 27B: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GPT-5 Pro for a larger context window (400K against 262K tokens).
No benchmark has tested both yet. GPT-5 Pro has results on WeirdML, Epoch Capabilities Index and ARC-AGI; Ternary Bonsai 2 27B has none yet. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
GPT-5 Pro
GPT-5 Pro takes 400K tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Ternary Bonsai 2 27B
GPT-5 Pro $0.075, Ternary Bonsai 2 27B $0.0003 per turn.
List prices
At a glance
- Coding index
- GPT-5 Pro not benchmarked, Ternary Bonsai 2 27B not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- GPT-5 Pro $120.00 against Ternary Bonsai 2 27B $0.50 per million output tokens, 240.0x apart.
- Context window
- GPT-5 Pro takes 400K tokens, Ternary Bonsai 2 27B 262K.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index1 board measured
| Benchmark | GPT-5 Pro | Ternary Bonsai 2 27B | Leader |
|---|---|---|---|
| WeirdML | 60.4% | Not measured | Only GPT-5 Pro measured |
| Neither model has a result on the other 38 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | GPT-5 Pro | Ternary Bonsai 2 27B | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 150.6 | Not measured | Only GPT-5 Pro measured |
| Neither model has a result on the other 1 board here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index5 boards measured
| Benchmark | GPT-5 Pro | Ternary Bonsai 2 27B | Leader |
|---|---|---|---|
| ARC-AGI | 70.2% | Not measured | Only GPT-5 Pro measured |
| ARC-AGI-2 | 18.3% | Not measured | Only GPT-5 Pro measured |
| SimpleBench | 61.6% | Not measured | Only GPT-5 Pro measured |
| Chess puzzles | 48.0% | Not measured | Only GPT-5 Pro measured |
| Kagi LLM Benchmark | 76.8% | Not measured | Only GPT-5 Pro measured |
| Neither model has a result on the other 17 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | GPT-5 Pro | Ternary Bonsai 2 27B | Leader |
|---|---|---|---|
| FrontierMath, tiers 1 to 3 | 55.8% | Not measured | Only GPT-5 Pro measured |
| FrontierMath, tier 4 | 19.5% | Not measured | Only GPT-5 Pro measured |
| Neither model has a result on the other 11 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Ternary Bonsai 2 27B costs less
Repository review
50K input + 3K output tokens
Ternary Bonsai 2 27B costs less
Agent loop
200K input + 10K output tokens
Ternary Bonsai 2 27B costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | OpenAI GPT-5 Pro | PrismML Ternary Bonsai 2 27B |
|---|---|---|
| Maker | OpenAI | Prism-ml |
| Weights | No public weights listed | Open weights |
| Released | October 6, 2025 | September 18, 2026 |
| Context window | 400K | 262K |
| Input $/Mtok | $15.00 | $0.075 |
| Output $/Mtok | $120.00 | $0.50 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5 Pro better than Ternary Bonsai 2 27B for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GPT-5 Pro for a larger context window (400K against 262K tokens).
Which is cheaper, GPT-5 Pro or Ternary Bonsai 2 27B?
GPT-5 Pro costs $15.00 per million input tokens and $120.00 per million output tokens; Ternary Bonsai 2 27B costs $0.075 and $0.50. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5 Pro or Ternary Bonsai 2 27B?
GPT-5 Pro, with 400K tokens against 262K.
Has any benchmark tested both GPT-5 Pro and Ternary Bonsai 2 27B?
No benchmark has tested both yet. GPT-5 Pro has results on WeirdML, Epoch Capabilities Index and ARC-AGI; Ternary Bonsai 2 27B has none yet. Compare them on price and context instead. Data as of October 22, 2026.