A Chinese 8B model beat the Western 8B models at Japanese RAG. I still wouldn't put it in the default deployment — and that distinction is the point.

Extends an earlier model-selection benchmark to three model families (Japanese / Western / Chinese) on a Japanese RAG task. Repo + raw results: https://github.com/elvisyao007/eval-driven-llm/tree/main/reports/model-selection-v2 An earlier post benchmarked local models for a Japanese RAG task and settled on selecting by constraint rather than raw capability. This post widens the field to three families — Japanese-tuned, Western open, and Chinese — and the result forces a distinction that matters more than any single score: model capability and deployment eligibility are two different questions, and conflating them is how people get model selection wrong. Same Japanese RAG task, same judge protocol, same discriminating golden set (oracle 87.5%, only 11% of questions answered by all models — it actually separates the field). hit@5, 8B class unless noted: Model Family hit@5 Swallow-8B Japanese-tuned ~0.53 Nemotron-9B-JP Japanese-tuned ~0.62 ELYZA-JP-8B Japanese-tuned ~0.40 deepseek-r1-8b Chinese ~0.51 Llama-3.1-8B Western ~0.22 Mistral-7B Western ~0.18 gemma4-31b Western (31B) ~0.62 Three things fall out of this, and they don't all point the same direction. 1. At 8B, Japanese fine-tuning is decisive — and generic Western models just aren't competitive The Western 8B models cratered: Llama-3.1-8B at 0.22, Mistral-7B at 0.18, against a Japanese-tuned average around 0.52. That's not a small gap; it's the difference between usable and not. This answers a question people sometimes ask skeptically — why do Japanese-specific models exist when Llama is right there? At the 8B scale, on a Japanese retrieval-grounded task, a generic Western model without Japanese fine-tuning is not in the running. The Japanese tuning is doing decisive work. One honest qualifier on the table: gemma4-31b (0.62) is the one Western model that holds up — but it's 31B, not 8B. It earns its score with 4× the parameters, not with Japanese optimization. So read the table in two tiers: within the 8B class,