ModelSpec is an analysis of alternatives for AI models: it decides which models fit a job from your requirements, sourced benchmarks and real cost, and shows its work.
Claude Opus 5.5 vs Qwen3.8 Max 0902 for High volume (quality first), as of 2026-09-23
Find a text model for many short assistant requests where response quality still leads the ranking.
Worked example as of 2026-09-23, from the public data image.
What the evidence says
The evidence can't separate them for this job.
Qwen3.8 Max 0902 has a 32% chance of matching or beating Claude Opus 5.5 on this job's objective.
probability bands: a model joins the leader when P(its score >= the leader's) >= 0.25 under the score posteriors; a weighted capability with an 80% interval wider than 2.8 is not enough evidence
Decision status: partial. P(best) and score intervals retain the full ranked lineup for this job, including models beyond this pair and models with thin evidence. Models with unknown objective values remain unranked and are outside this probability. P(best) is not a head-to-head probability.
Scores and score intervals use the objective's dimensionless normalised units. Cost per task is in USD for the selected offering and the applied spec's task size. When task size is omitted, the engine uses its documented default. Unavailable means the engine returned no value.
| Model | Score | Score interval | P(best), ranked job lineup | Cost per task, USD | Selected offering: provider / region / tier | Capability estimates and intervals |
|---|---|---|---|---|---|---|
| Claude Opus 5.5 | 0.884932 | [0.71708, 1.052783] | 49% | 0.018 | anthropic / global / standard |
|
| Qwen3.8 Max 0902 | 0.79648 | [0.628628, 0.964331] | 15% | 0.007 | alibaba-model-studio / singapore / standard |
|
Short requests at scale; quality leads, cost counts.
Requirements
model.class = text-generator: The workload needs generated text responses.
Preferences
chat_preference: Prefer assistants whose responses people rate more highly.-offering.cost_per_task: At volume, cost still matters as the second term.
Applied template spec
spec_version- 1
where- model.class = text-generator
optimizeweightschat_preference- 0.7
-offering.cost_per_task- 0.3
task_tokensinput- 2000
output- 500
Evidence for Claude Opus 5.5
| Benchmark | Version | Measurement | Unit | Published interval | Evidence date | Measurement conditions | Provenance |
|---|---|---|---|---|---|---|---|
| arena_webdev | webdev / overall, latest split, revision 1880dbebff5b | 1818.41 | Arena score (Elo scale) | Unavailable | 2026-09-23 |
| Source |
Missing facts for Claude Opus 5.5
model.hardware_fit_indeterminate: unknownmodel.languages: unknownmodel.parameters_total: unknownorigin.base_lineage: not_disclosedorigin.weights_hosting: not_disclosedoffering.api_model_id: unknownoffering.data.zero_retention: requires_contractoffering.private_deployment: unknownoffering.router_slug: unknownoffering.speed.throughput: unknownoffering.speed.time_to_first_token: unknown
Evidence for Qwen3.8 Max 0902
| Benchmark | Version | Measurement | Unit | Published interval | Evidence date | Measurement conditions | Provenance |
|---|---|---|---|---|---|---|---|
| arena_webdev | webdev/latest, overall | 1660.58 | Arena score (Elo scale) | Unavailable | 2026-09-23 |
| Source |
Missing facts for Qwen3.8 Max 0902
model.hardware_fit_indeterminate: unknownmodel.languages: unknownmodel.parameters_total: unknownorigin.base_lineage: not_disclosedorigin.lab_jurisdiction: not_disclosedorigin.weights_hosting: not_disclosedoffering.api_model_id: unknownoffering.attestation.baa: not_disclosedoffering.attestation.soc2: not_disclosedoffering.data.retention: not_disclosedoffering.data.zero_retention: not_disclosedoffering.price.batch_input: not_disclosedoffering.price.batch_output: not_disclosedoffering.price.cached_input: not_disclosedoffering.private_deployment: unknownoffering.router_slug: unknownoffering.speed.throughput: unknownoffering.speed.time_to_first_token: unknown
What this template teaches
Short task tokens make the cost term reflect one small request, not one long agent run.
Decision dec_f0ebf8d327afab69afc0e656 on public snapshot snap_05a963d2477ac2fb.
Read the full dated job answer.
The live board uses current data. This link applies the template to its full lineup.
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