Llama-3.2-3B semiconductor technical writer (Unsloth QLoRA, merged)

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Merged QLoRA fine-tune of meta-llama/Llama-3.2-3B-Instruct for semiconductor and data-center interconnect technical-marketing and documentation style (Ethernet adapters, switch silicon, DPU / storage-adapter user guides).

Trained with Unsloth FastLanguageModel + TRL SFTTrainer on an RTX 3090 (fp16). Base weights were loaded from unsloth/Llama-3.2-3B-Instruct (unsloth-bnb-4bit).

This is the inference repo (fp16 merged weights). Load it with AutoModelForCausalLM, Unsloth, or convert/use the published Q4_K_M GGUF in Ollama / llama.cpp.

This is not an official vendor product. It is a specialist adapter trained on a private mix of extracted vendor PDFs plus cleaned synthetic docs. It will still invent SKUs if you ask it to write a brief for a product that was thin or noisy in the gold data.

Companion artifacts from the same run:

Change the ids if you publish under different names. Llama 3.2 Community License requires distributed model names to start with Llama.

What it is for

• Product briefs, datasheet feature lists, application notes
• Host / adapter CLI style user-guide sections
• Spec extraction and short grounded QA over a pasted excerpt
• Internal draft generation that should stay on-genre and internally consistent (one process node, one primary throughput, one form factor)

Not for:

• Authoritative datasheet numbers without a human / source check
• Legal, safety, or customer-facing specs shipped as-is
• Languages other than English
• General chat outside semiconductor interconnect / storage / DPU content

Load and run (Transformers)

Use the Llama 3.2 Instruct chat template. Do not hand-roll Qwen ChatML (<|im_start|>). The SFT JSONL is ChatML-shaped (messages[{role, content}]); training ran it through tokenizer.apply_chat_template.

import torch
from transformers import AutoModelForCausalLM, AutoTokenizer

REPO = "Shankarblr/Llama-3.2-3B-TechWriter-Instruct-Unsloth"

tokenizer = AutoTokenizer.from_pretrained(REPO)
if tokenizer.pad_token is None:
    tokenizer.pad_token = tokenizer.eos_token

model = AutoModelForCausalLM.from_pretrained(
    REPO,
    torch_dtype=torch.float16,
    device_map="auto",
)

messages = [
    {
        "role": "system",
        "content": (
            "You are a technical marketing and documentation writer for semiconductor "
            "and data-center interconnect products. "
            "Write clear, structured content in a consistent house style. "
            "Match the requested document type. Keep specifications internally consistent: "
            "one process node, one primary throughput, and one form factor unless the "
            "source explicitly lists options. Do not invent conflicting SKUs or CLI syntax."
        ),
    },
    {
        "role": "user",
        "content": "Draft a product brief covering a 10/25/40GbE converged network adapter family.",
    },
]

prompt = tokenizer.apply_chat_template(
    messages, tokenize=False, add_generation_prompt=True
)
inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
out = model.generate(
    **inputs,
    max_new_tokens=1024,
    do_sample=False,
    pad_token_id=tokenizer.eos_token_id,
)
print(tokenizer.decode(out[0][inputs["input_ids"].shape[1]:], skip_special_tokens=True))

Unsloth FastInference (adapter or merged)

from unsloth import FastLanguageModel

model, tokenizer = FastLanguageModel.from_pretrained(
    model_name="Shankarblr/Shankarblr/Llama-3.2-3B-TechWriter-Instruct-Unsloth",
    max_seq_length=2048,
    load_in_4bit=True,
)
FastLanguageModel.for_inference(model)

If you see Both max_new_tokens and max_length, the shipped generation_config.json still has a leftover max_length (Unsloth/Transformers 5.x may set a very large default). Pass only max_new_tokens at generate time. Greedy decode (do_sample=False) ignores leftover temperature / top_p.

Ollama / GGUF (Q4_K_M)

Same run exported:

llama-3.2-3b-instruct.Q4_K_M.gguf

Start on Q4. Re-export q8_0 only if Ollama garbles numbers or SKUs that the fp16 merge gets right. Wrong product family on both fp16 and Q4 is a dataset issue, not a quant issue.

cd <gguf-output-dir>   # Unsloth may add an extra _gguf suffix to the folder name
ollama create llama32-tech-writer -f Modelfile
ollama run llama32-tech-writer

The Modelfile must use Llama 3.2 headers, not Qwen ChatML:

FROM ./llama-3.2-3b-instruct.Q4_K_M.gguf
TEMPLATE """{{ if .System }}<|begin_of_text|><|start_header_id|>system<|end_header_id|>

{{ .System }}<|eot_id|>{{ end }}<|start_header_id|>user<|end_header_id|>

{{ .Prompt }}<|eot_id|><|start_header_id|>assistant<|end_header_id|>

{{ .Response }}<|eot_id|>"""
PARAMETER stop "<|eot_id|>"
PARAMETER stop "<|end_of_text|>"
PARAMETER temperature 0
PARAMETER num_ctx 2048

Training

Unsloth logged “double BOS tokens” and stripped one automatically. Vocab was not resized.

Eval (teacher-forced next token, not open generation)

Eval still improved epoch 2 → 3, so the published weights are the final step, not an early-stop. This Unsloth run did not log mean token accuracy (the earlier bitsandbytes SFT run did: 0.9513 @ loss 0.1313). Do not compare the two eval losses as a bake-off without a shared open-generation rubric — response-only masking changes the loss scale.

Read eval loss correctly. 0.16 means “next-token fit on held-out ChatML.” It is not factual accuracy on product SKUs.

Open-generation notes from the train-job smoke tests

Greedy Unsloth inference after merge (fp16 adapter path):

• Adapter product brief — house style and section skeleton are on-genre, but the draft mixed later-generation 100/200/400G, PAM4 SerDes, and CXL language into an older 10/25/40GbE CNA family. Treat as a style draft, not a spec source.
• CLI QoS section — user-guide cadence is right; the model started from an adjacent speed-setting command and then drifted into QoS info. Extracted CLI gold is more reliable than generated flag mashups.

Those failures showed up before GGUF quantization. Do not “fix” them by exporting Q8 or by training more epochs on the same mix.

Dataset mix (private ChatML SFT)

6,765 rows after dropping dirty synthetic gold (multi-node, multi-throughput, grammar doubles, stubs).

Doc types: user_guide 2,772 · product_brief 2,528 · datasheet 613 · application_note 305 · technology_brief 229 · white_paper 222 · competitive_report 96.

Extracted PDFs cover adapter user guides, host CLI, Ethernet switch-silicon briefs, high-radix switch throughput claims, and silicon root-of-trust notes. A large share of generate gold is still synthetic house-style prose, so the model can emit invented series names if the prompt does.

Intended prompt style

Train-time system prompts:

1. Writer — semiconductor / interconnect house style; one process node / throughput / form factor.
2. Editor — revise copy; do not add contradictory specs.
3. Product specialist — answer only from the pasted excerpt; otherwise say you cannot determine it.

Match those at inference. Grounded QA quality collapses if you drop the specialist system prompt.

Limitations

• 3.21B parameters. Long, consistent datasheets still drift.
• Synthetic SKUs in the pre-clean pool taught a habit of mixing product families (see the CNA brief smoke test). The recommended set drops the worst contradictions; it does not delete every invented or cross-wired family.
• Extracted CLI gold is the reliable part. Treat generated flags and WWPNs as drafts.
• No DPO / GRPO on this published checkpoint (those datasets exist separately).
• Eval is teacher-forced loss only. Judge drafts with held-out brief / CLI / grounded-QA prompts, then compare fp16 vs Ollama Q4 before touching quant.
• Adapter reload needs the gated Meta base (or the Unsloth 4-bit twin). Merged inference does not call Meta’s repo.

Files to upload (merged repo)

Optional: upload llama-3.2-3b-instruct.Q4_K_M.gguf + Modelfile as extra files, or put GGUF on a *-GGUF repo.

Do not upload checkpoint-*, optimizer.pt, rng_state.pth, or the 4-bit train-time weights.

Related

• Base: meta-llama/Llama-3.2-3B-Instruct
• Train-time weights: unsloth/Llama-3.2-3B-Instruct
• Method: Unsloth QLoRA + TRL SFT, train_on_responses_only
• Adapter: Shankarblr/Llama-3.2-3B-Unsloth-LoRA
• Prior bitsandbytes SFT (same data): Shankarblr/Llama-3.2-3B-Instruct-SFT
• Sister Qwen run on the same private mix: Shankarblr/qwen2.5-1.5b-instruct-sft
• Optional next stage: DPO / GRPO with the Llama chat template

License

Built with Llama

Llama 3.2 is licensed under the Llama 3.2 Community License, Copyright © Meta Platforms, Inc. All Rights Reserved.

Use of this model is also subject to the Llama 3.2 Acceptable Use Policy.

This checkpoint is an unofficial style model. It is not affiliated with, endorsed by, or a product of any semiconductor vendor whose public documentation may have been in the training mix.