Model comparison
Composer 2 Fast vs GPT-OSS 120B
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Composer 2 Fast unranked (Not scored); GPT-OSS 120B #122 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Composer 2 Fast and GPT-OSS 120B share 1 comparable benchmark result. 0 of 8 categories are comparable. 0 results are unique to Composer 2 Fast; 27 to GPT-OSS 120B.
Updated July 28, 2026- Shared results
- 1
- Composer 2 Fast only
- 0
- GPT-OSS 120B only
- 27
- Comparable categories
- 0 / 8
Benchmark data for Composer 2 Fast and GPT-OSS 120B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Composer 2 Fast has the larger context window at 200K, compared with 128K for GPT-OSS 120B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Composer 2 Fast | GPT-OSS 120B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Composer 2 FastNot available | GPT-OSS 120B$0 input / $0 output | A complete price comparison is not available. |
| Generation speedtokens per second | Composer 2 FastNot available | GPT-OSS 120B262 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Composer 2 FastNot available | GPT-OSS 120B0.79 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Composer 2 Fast200K | GPT-OSS 120B128K | Composer 2 Fast lists the larger context window. |
Benchmark Deep Dive
Agentic10 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| AA Agentic IndexSource | — | 13.2% | Not comparable |
| APEX-Agents-AASource | — | 3.1% | Not comparable |
| τ²-bench resultsSource | — | 65.8% | Not comparable |
| GDPval-AASource | — | 15.1% | Not comparable |
| GDPval-AASource | — | 802 | Not comparable |
| Gert LabsSource | — | 29.61% | Not comparable |
| AA ITBenchSource | — | 5.6% | Not comparable |
| AA EnterpriseOps-GymSource | — | 25.5% | Not comparable |
| AA Harvey LABSource | — | 13.9% | Not comparable |
| terminalBenchHardSource | — | 23.5% | Not comparable |
Coding4 benchmarks
Reasoning2 benchmarks
Knowledge8 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | — | 23.8% | Not comparable |
| AA-GPQA DiamondSource | — | 78.2% | Not comparable |
| AA-HLESource | — | 18.5% | Not comparable |
| AA-Omniscience IndexSource | — | -50.0% | Not comparable |
| AA-Omniscience AccuracySource | — | 21.5% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 91.2% | Not comparable |
| AA Openness IndexSource | — | 38.9% | Not comparable |
| AA MMLU-ProSource | — | 80.8% | Not comparable |
Math1 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| AA AIME 2025Source | — | 93.4% | Not comparable |
Multilingual1 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | — | 82.8% | Not comparable |
Multimodal1 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| Design Arena WebsiteSource | — | 993 | Not comparable |
Inst. Following1 benchmarks
| Benchmark | Composer 2 Fast | GPT-OSS 120B | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 69.0% | Not comparable |
Frequently Asked Questions (3)
Can I compare Composer 2 Fast and GPT-OSS 120B on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Composer 2 Fast and GPT-OSS 120B today?
GPT-OSS 120B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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