Broken-Tutu-24B_Compressed-Tensors

Broken-Tutu-24B — Quantized (compressed-tensors for vLLM)

This repository provides quantized runtime builds of
ReadyArt/Broken-Tutu-24B (marked “not for all audiences”), repackaged for vLLM using the compressed-tensors format.

TL;DR

• Six branches covering INT4 (W4A16) and INT8 (W8A16) with group sizes 32 / 64 / 128.
• Same calibration recipe as our recent cards: 512 chat samples, 2048 max sequence length, dataset neuralmagic/LLM_compression_calibration (messages rendered with the model’s chat template).
• Weight-only AWQ; lm_head kept high-precision; exported with save_compressed=True for vLLM.

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Revisions & Branches

The main branch is a landing page (model card + links). Runnable artifacts live in per-quant branches.

• main — placeholder / landing page
• W4A16_GS32 — INT4 weights / A16 activations, group size 32 (highest fidelity)
• W4A16_GS64 — INT4 / A16, group size 64 (balanced)
• W4A16_GS128 — INT4 / A16, group size 128 (leanest INT4)
• W8A16_GS32 — INT8 / A16, group size 32 (max fidelity for INT8)
• W8A16_GS64 — INT8 / A16, group size 64 (balanced INT8)
• W8A16_GS128 — INT8 / A16, group size 128 (leanest INT8)

Quick links

• main: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/main
• W4A16_GS32: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W4A16_GS32
• W4A16_GS64: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W4A16_GS64
• W4A16_GS128: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W4A16_GS128
• W8A16_GS32: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W8A16_GS32
• W8A16_GS64: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W8A16_GS64
• W8A16_GS128: https://huggingface.co/TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors/tree/W8A16_GS128

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What’s inside (per revision)

• Sharded quantized weights (*.safetensors) + index (model.safetensors.index.json)
• config.json with compressed-tensors metadata (weight_format, quantization, quantization_config, etc.)
• Tokenizer artifacts (tokenizer.json, tokenizer.model, merges/vocab as applicable)
• Optional: chat_template.jinja (inherits the finetune’s chat style)

Exact file lists may differ between branches — see Files and versions for each revision.

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Quantization & calibration details (same script/recipe family as prior cards)

Method / flow

• llmcompressor oneshot pipeline with an AWQModifier (weight-only quantization).

Targets / exclusions

• Quantize Linear layers; ignore lm_head (kept high-precision).

Weights / grouping

• Branches W4A16_* use INT4 (num_bits=4, symmetric=True).
• Branches W8A16_* use INT8 (num_bits=8, symmetric=True).
• Strategy: "group" with group size ∈ {32, 64, 128} according to branch.
• Activations not quantized (runtime A16: BF16/FP16).
• Export with save_compressed=True so vLLM loads the compressed-tensors layout directly.

Calibration dataset & preprocessing

• Dataset: neuralmagic/LLM_compression_calibration, split train.
• NUM_CALIBRATION_SAMPLES = 512 (random subset with fixed seed).
• MAX_SEQUENCE_LENGTH = 2048.
• Each sample’s messages list is rendered via tokenizer.apply_chat_template(..., tokenize=False), then tokenized with:
  • max_length=2048, truncation=True, padding=False, add_special_tokens=False.

Compression call

• oneshot(..., max_seq_length=2048, num_calibration_samples=512, tokenizer=tokenizer) on the preprocessed dataset.

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Why group size matters in AWQ (W4A16 / W8A16)

• Definition: Group size controls how many consecutive weights share a single set of quantization scales.
• Trade-offs (accuracy ↔ throughput/VRAM):
  • GS32 (smallest groups): Most scale sets → highest fidelity (often best perplexity/task scores), but more scale metadata and slightly lower throughput.
  • GS64 (middle ground): Good balance of quality and performance; a solid default if you haven’t profiled yet.
  • GS128 (largest groups): Fewest scales → leaner/faster (less bandwidth/metadata), with slightly higher quantization error; good for throughput-critical serving.
• Bit-width differences:
  • W4A16 tends to be smaller/faster than INT8 at the same GS, but can be more sensitive to GS and calibration coverage.
  • W8A16 offers more headroom (often closer to FP in quality), at the cost of more VRAM/bandwidth.

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Context length

• Calibration context: up to 2048 tokens per sample (as above).
• Model context window: inherited from ReadyArt/Broken-Tutu-24B; quantization does not change rope/position encodings—only the numeric representation of the weights.

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Quickstart — vLLM (compressed-tensors)

Install vLLM (recent version recommended):

pip install vllm

Serve (adjust to your hardware):

CUDA_VISIBLE_DEVICES=0,1,2,3 \
vllm serve TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors \
  --quantization compressed-tensors \
  --tensor-parallel-size 4 \
  --max-model-len 2048 \
  --gpu-memory-utilization 0.70 \
  --dtype bfloat16

Example Chat Completions:

curl http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "TheHouseOfTheDude/Broken-Tutu-24B_Compressed-Tensors",
    "messages": [
      {"role":"system","content":"You are Broken-Tutu — helpful, precise, and safe."},
      {"role":"user","content":"Draft a short, character-driven opening in under 200 words."}
    ],
    "max_tokens": 512,
    "temperature": 0.7,
    "top_p": 0.95
  }'

Note: compressed-tensors is a vLLM runtime format. Loading directly with vanilla 🤗 Transformers is not supported.
For Transformers, use a compatible export (e.g., GPTQ/AWQ) or the full-precision finetune.

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Prompting / chat template

This package follows the finetuned parent’s chat conventions. If a chat_template.jinja is present, libraries that support apply_chat_template will automatically format messages.

Guidelines:

• Keep the system message concise (behavior, tone, safety constraints).
• Provide clear user instructions; for multi-step tasks, list steps explicitly.

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Intended use & safety

This quantization:

• Does not change underlying behavior or content tendencies.
• Only changes weight storage for efficient inference.

Because the base is flagged “not for all audiences,” apply appropriate content filters / policies for your deployment context.

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Lineage

• Finetuned parent: https://huggingface.co/ReadyArt/Broken-Tutu-24B
• This repo: Quantized child of the finetune (compressed-tensors for vLLM)

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Hardware tips

• 24B models benefit from multi-GPU tensor parallel for throughput.
• Long contexts are KV-cache heavy — tune --max-model-len and batch size.
• Prefer BF16 on GPUs with native support; otherwise FP16.
• Enable P2P/NVLink when available; consider CUDA Graphs if stable.

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Changelog

• v1 (current) — Initial compressed-tensors release; branches
  W4A16_GS32 / W4A16_GS64 / W4A16_GS128 / W8A16_GS32 / W8A16_GS64 / W8A16_GS128 with 512-sample / 2048-token AWQ calibration; vLLM-ready packaging.