Quantization
Table | |
|---|
| Method | GPTQ, LLM Compressor 0.14.0, compressed-tensors 0.19.0 |
| Scheme | W4A16: int4 symmetric weights, group size 128, static activation ordering; BF16 activations |
| Quantized | All 448 Linear layers in the 64 decoder layers (q/k/v/o, gate/up/down) |
| Kept in BF16 | lm_head, embeddings, norms (byte-identical to the original) |
| Calibration | 256 documents x 1024 tokens: 128 from C4 English and 128 from mC4 Japanese (train shard 0) |
| Hardware | 8x H100 80 GB (one AWS p5.48xlarge), 8-rank distributed GPTQ, 237 s |
The full recipe is in recipe.yaml.
Usage
The tokenizer is a custom class shipped with the original repository (llmjp4_tokenizer.py), so trust_remote_code is required. The vllm_plugins/ directory and chat template are copied unchanged from the original.
vllm serve ronantakizawa/ELYZA-Thinking-1.0-llm-jp-4-33b-w4a16-gptq --trust-remote-code --max-model-len 8192
Tested with vLLM 0.30.0 on H100, where it loads as CompressedTensorsWNA16 with the Machete kernel.
Evaluation
BF16 original vs this checkpoint, both served by vLLM 0.30.0 and scored with lm-evaluation-harness 0.4.13 (local-completions, default few-shot settings, seed 1234). A flip is a question one model answers correctly and the other does not.
Table with columns: Task, BF16, W4A16, Δ, Flips| Task | BF16 | W4A16 | Δ | Flips |
|---|
| MMLU (acc, 14,042) | 73.14 | 72.58 | −0.56 | 5.9% |
| HellaSwag (acc_norm, 10,042) | 81.40 | 80.88 | −0.52 | 2.3% |
| ARC-Challenge (acc_norm, 1,172) | 61.35 | 60.41 | −0.94 | 3.7% |
| GSM8K 5-shot (flexible, 1,319) |
MGSM-ja has only 250 questions (standard error about ±3.1 points), so its difference is within noise.
Token-level comparison on 100 held-out C4 validation documents x 1024 tokens per language (102,300 scored positions each):
Table with columns: English, Japanese | English | Japanese |
|---|
| Perplexity, BF16 → W4A16 | 11.05 → 13.00 | 16.81 → 22.82 |
| Top-1 token agreement with BF16 | 89.9% | 86.6% |
| BF16 top-1 within W4A16 top-5 | 98.4% | 96.5% |
| Mean KL(BF16 ‖ W4A16), over BF16 top-20 | 0.075 | 0.137 |
Japanese degrades more than English on every token-level measure. The calibration set covered 19.6% of the 196,608-token vocabulary; a larger or chat-formatted calibration set may close part of that gap. This was not tested.
License and attribution
Apache-2.0, the same license as the original. LICENSE and NOTICE are copied unchanged from elyza/ELYZA-Thinking-1.0-llm-jp-4-33b. All credit for the model belongs to ELYZA, Inc. and the LLM-jp project (National Institute of Informatics).