Quantization Policy
Qwythos is based on Qwen3.5, whose hybrid attention stack contains linear-attention and attention modules that should remain in native precision for vLLM loading. For this reason, this export intentionally quantizes only the text MLP projection weights.
Table with columns: Scope, Format| Scope | Format |
|---|
Text MLP gate_proj | W4A16 AWQ, group size 128, zero point |
Text MLP up_proj | W4A16 AWQ, group size 128, zero point |
Text MLP down_proj | W4A16 AWQ, group size 128, zero point |
| First text layer | Native BF16/FP16 |
linear_attn.* | Native BF16/FP16 |
self_attn.* | Native BF16/FP16 |
| Embeddings, norms, rotary embeddings | Native BF16/FP16 |
lm_head | Native BF16/FP16 |
| Vision / visual modules | Native BF16/FP16 |
| MTP / special heads, if present | Native BF16/FP16 |
Quantization config used by the exporter:
w_bit: 4q_group_size: 128zero_point: trueawq_grid_size: 8awq_samples: 8calibration_mode: data_freemax_shard_size: 3GB
The exporter keeps the Qwen3.5 linear-attention tensors in their official split layout rather than fusing them, which is important for vLLM compatibility.
Dependencies
Recommended vLLM serving stack:
pip install --upgrade vllm transformers accelerate safetensors
Qwen3.5 support in serving frameworks is still relatively new. If your local vLLM build cannot load qwen3_5, upgrade vLLM and Transformers first.
vLLM Startup Command
Start with a conservative context length on a single RTX 4090. The source model advertises a 1M context window, but KV cache memory, not AWQ weight size, becomes the limiting factor at long context.
vllm serve JunHowie/Qwythos-9B-Claude-Mythos-5-1M-AWQ \ --host 0.0.0.0 \ --port 8000 \ --served-model-name Qwythos-9B-AWQ \ --trust-remote-code \ --quantization awq \ --dtype float16 \ --max-model-len 32768 \ --gpu-memory-utilization 0.85
If memory headroom is sufficient, increase --max-model-len gradually.
Example Request
curl http://localhost:8000/v1/chat/completions \ -H "Content-Type: application/json" \ -d '{ "model": "Qwythos-9B-AWQ", "messages": [ { "role": "user", "content": "Explain how AWQ quantization protects salient channels, and why Qwen3.5 linear-attention tensors are kept native." } ], "temperature": 0.6, "top_p": 0.95, "max_tokens": 4096 }'
Model Download
from huggingface_hub import snapshot_download snapshot_download( "JunHowie/Qwythos-9B-Claude-Mythos-5-1M-AWQ", cache_dir="your_local_path",)
Notes
- This is a quantized derivative of Qwythos-9B-Claude-Mythos-5-1M, not a new fine-tune.
- The original model is a reasoning model and may emit
<think>...</think> blocks before the final answer.
- Recommended sampling follows the base model card:
temperature=0.6, top_p=0.95, top_k=20, repetition_penalty=1.05.
- The source model advertises a 1,048,576-token context window with YaRN rope scaling. For this AWQ release, start smaller on consumer GPUs and raise context length after memory testing.
- No benchmark numbers are changed or claimed by this AWQ export. Use the original model card for upstream capability references.
Quantization Log
2026-06-301. Quantized empero-ai/Qwythos-9B-Claude-Mythos-5-1M on RTX 4090.2. Exported AWQ GEMM W4A16 weights with group size 128 and zero point.3. Used data-free AWQ search; no calibration dataset was involved.4. Kept Qwen3.5 attention, linear-attention, embeddings, norms, lm_head, visual modules, and first text layer in native precision for vLLM compatibility.
Original Model Overview
Qwythos-9B is developed by Empero. It is a full-parameter reasoning model built on top of a deeply uncensored Qwen3.5-9B base and post-trained on over 500 million tokens of Claude Mythos and Claude Fable traces, with chain-of-thought generated by Empero AI's internal tool rethink.
Key upstream features:
- 1,048,576-token context via YaRN rope scaling enabled by default.
- Native function calling following Qwen3.5's tool-use format.
- Reasoning-oriented behavior with
<think> blocks.
- Strong gains over the base Qwen3.5-9B in the original evaluation setup, especially on MMLU and GSM8K.
- Domain emphasis on cybersecurity, biomedical, quantitative reasoning, coding, and agentic workflows.
Original evaluation headline from the base model card:
Table with columns: Task, Metric, Base Qwen3.5-9B, Qwythos-9B, Delta| Task | Metric | Base Qwen3.5-9B | Qwythos-9B | Delta |
|---|
| gsm8k | exact_match flexible | 0.670 | 0.860 | +0.190 |
| gsm8k | exact_match strict | 0.510 | 0.810 | +0.300 |
| mmlu | acc | 0.232 | 0.575 | +0.343 |
|
These numbers belong to the original FP/BF16 model card and are included only as upstream reference.
Base Model Details
Limitations
- This AWQ export has not been presented as a full formal benchmark release.
- Very long context still requires substantial KV-cache memory.
- For exact identifiers, safety-critical medical details, live facts, or security-sensitive workflows, pair the model with retrieval/tools and verify outputs.
- Qwythos is intentionally uncensored. Add application-level policy and review layers for public-facing deployments.
Acknowledgements