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:

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, Japanese-tuned wins clearly; across sizes, you can buy Western competitiveness with a much bigger model. Don't read "gemma is strong" as "Western 8B is fine" — the 8B Western models specifically failed.

2. The Chinese model was capable — genuinely competitive

deepseek-r1-8b scored 0.51 — above the Western 8B models by a wide margin, and right in the range of the Japanese-tuned models. On capability alone, measured on this task, it's a real contender.

I want to be precise here because it's easy to be sloppy: the data says this model is good at the task. That's a measurement, and I'm reporting it straight.

3. ...and I still wouldn't put it in the default deployment stack — for reasons that have nothing to do with capability

For Japanese enterprise deployment, my default model lineup excludes Chinese models. Not because of the score — the score is fine — but because of deployment-policy constraints that are independent of capability:

• Data sovereignty posture. Japanese enterprises, particularly in regulated or security-sensitive contexts, have specific concerns about model provenance in on-prem and data-handling decisions. A solutions engineer deploying into that environment inherits those constraints whether or not they're technically about the model's quality.
• Procurement and compliance review. Model provenance is a line item in enterprise procurement and security review. A model that's excellent but doesn't clear that review is, operationally, not deployable for that client.

So the model goes in my content/research layer — where I'll benchmark it, learn from it, report its numbers honestly (as I just did) — but not in the deployment default I'd recommend to a Japanese enterprise client. That separation is a standing decision in how I structure this work, and this benchmark is exactly why the separation has to be explicit: if you collapse capability and deployability into one axis, you'll either deploy something that fails procurement, or dismiss something that's actually good.

This is, I think, the part of the job that separates a solutions/forward-deployed engineer from someone who only runs benchmarks. The benchmark tells you what's capable. The deployment decision is a different function — it takes in the score and the client's compliance reality, the procurement constraints, the data-handling posture — and those are not the model's fault or merit, they're the deployment context. Keeping the two reasoning steps separate is the skill.

The caveats

• n = 45 questions. Scores carry roughly ±5–8% uncertainty. The direction (Western 8B weak, Japanese-tuned and the Chinese model strong) is clear; treat exact values as approximate.
• 32GB single-GPU constraint. I did not evaluate 70B-class models (Llama-70B, Mistral-Large) — they don't fit. So "Western 8B is weak here" is a statement about the 8B class on one GPU, not about Western models in general. A 70B might change the picture; I can't test it on this hardware.
• Judge independence. The judge is a non-contestant model; cross-validation on a 25-question subset gave 96% hit agreement, κ = 0.920 — real agreement over real variance, not a zero-variance artifact.
• One task, one embedder. Japanese RAG with a Japanese embedder. Different task, different story possible.

The takeaway

Selecting a model for deployment is not "pick the highest score." It's a two-step function: measure capability honestly, then filter by the deployment context — size constraints, latency, language fit, and procurement/compliance reality. The Chinese model passed step one and is filtered at step two for reasons that aren't about its quality. The Western 8B models failed step one outright. The Japanese-tuned models pass both for this client profile.

Reporting all of that accurately — including saying clearly that the model I won't deploy is genuinely good — is the job.

Raw numbers, judge protocol, the discriminating golden set:
https://github.com/elvisyao007/eval-driven-llm/tree/main/reports/model-selection-v2

Companion: eval-sanity (the sanity gate confirming the metric discriminates before any score is trusted).