Qwen3.6-27B-uncensored-heretic-v2 — W8A8 (AutoRound INT8 Dynamic, MTP preserved)

Overview

Qwen3.6-27B-uncensored-heretic-v2-Native-MTP-Preserved-W8A8 is an 8-bit checkpoint designed to reduce inference memory requirements, published by groxaxo. It is intended for open-source evaluation, reproducible experimentation, and compatible local or hosted inference workflows. The wording below is deliberately limited to what can be verified from this repository's metadata and artifacts.

The repository name identifies a behavior-modified or reduced-filtering lineage. That label describes the source or conversion history; it is not a guarantee of unrestricted behavior in every prompt or runtime. Test outputs carefully before sharing or deploying them.

At a glance

What is included

• *.safetensors (11 files)
• config.json
• generation_config.json
• tokenizer.json
• tokenizer_config.json
• processor_config.json
• chat_template.jinja
• quantization_config.json
• Additional configuration, tokenizer, processor, or shard files (20 visible artifacts total)

Quick start

Runtime selection

Load the checkpoint with a runtime that supports its architecture and 8-bit weight format. Keep the repository's configuration and tokenizer/processor files together with the weight files.

Compatibility and responsible use

• Use a runtime that explicitly supports this format, architecture, and modality.
• Keep configuration, tokenizer, processor, projection, and weight files from the same revision together.
• Review the source model card and license before redistribution or deployment.
• Hardware needs depend on parameter count, context length, cache precision, quantization, and concurrency.
• Report reproducible issues with the runtime version, hardware, launch command, and a minimal example.

Quantization or conversion changes numerical behavior, memory use, and throughput relative to the source checkpoint; validate quality on your own workload.

Generated outputs may be inaccurate or unsuitable for a given use case. Users are responsible for testing behavior, applying appropriate safeguards, and complying with applicable licenses and laws.

INT8 W8A8 dynamic (per-token activation) quantization of llmfan46/Qwen3.6-27B-uncensored-heretic-v2-Native-MTP-Preserved, produced with AutoRound 0.13.1 and exported in the compressed-tensors (auto_round:llm_compressor) format for vLLM.

Same recipe as the Darwin-28B W8A8 build.

Quantization recipe

• Scheme: INT8 — channel-wise INT8 weights, INT8 dynamic per-token activations (CUTLASS INT8 path in vLLM).
• Algorithm: RTN (round-to-nearest, data-free). INT8 + dynamic activations are near-lossless.
• Quantized: language-model Linear weights only (DeltaNet in_proj_*/out_proj + full-attn q/k/v/o_proj + MLP gate/up/down).
• Preserved in BF16: native MTP module (mtp.*, via --ignore_layers mtp), the vision tower (model.visual.*, auto-skipped by AutoRound's text-module-only VLM path), lm_head, embed_tokens, all norms.
• Hardware: 2 × RTX 3090.

Architecture: Qwen3.5-generation hybrid (qwen3_5, 64 layers, 3:1 DeltaNet/full-attention, hidden 5120, vocab 248320), multimodal, with a 1-layer native MTP head for speculative decoding.

Serving (vLLM, TP2) — recommended: dense (no MTP)

vllm serve groxaxo/Qwen3.6-27B-uncensored-heretic-v2-Native-MTP-Preserved-W8A8 \
  --tensor-parallel-size 2 \
  --max-model-len 262144 \
  --kv-cache-dtype fp8 \
  --reasoning-parser qwen3 \
  --trust-remote-code

MTP note (measured)

The native MTP head is preserved in BF16, but on this finetune it is non-predictive: measured ~0% draft-token acceptance (2 of 6254), so enabling speculative decoding is actually slower (~22.5 tok/s with MTP vs ~27.7 tok/s dense, single-stream on 2×RTX 3090). This was isolated to the checkpoint's MTP head, not the quantization or server:

• Same vLLM + method:mtp on the standard Qwen3.6-27B (AEON FP8) gives 78% acceptance / ~2.1× speedup — so the setup is correct.
• 0% acceptance persists with kv-cache-dtype=auto (not a KV-quant artifact).
• The W8A8 quant is near-lossless (KL≈0.02 nats/token) and preserves the MTP head structure intact.

The heretic-v2 finetune appears to have diverged its main weights from the base MTP head, so the head's drafts no longer match. Serve dense for best speed. The MTP weights remain in this repo for anyone who retrains/distills the head against this finetune. The vision tower is intact (drop --hf-overrides '{"language_model_only": true}' to use it; add it to save VRAM for text-only).