Qwythos-9B-Claude-Mythos-5 — 1M Context Open-Source Reasoning Model
- URL: https://www.threads.com/@akiraxtwo/post/DZ5QrfIEs1T
- Date Saved: 2026-06-23
- Source: Threads (@akiraxtwo)
- Tags: local-llm, ai-tools
Summary
Empero released Qwythos-9B-Claude-Mythos-5-1M, a full-parameter fine-tune based on a deeply uncensored Qwen3.5-9B.
Key specs:
- Context: 1,048,576 tokens (1M) via YaRN
- Training data: 500M+ tokens of Claude Mythos/Fable synthetic CoT data
- Full-parameter fine-tune (not LoRA)
- Benchmarks vs base Qwen3.5-9B: MMLU +34, gsm8k-strict +30
Hardware requirements (inference):
- Q4KM quant: ~5.3GB VRAM (6-8GB GPU minimum)
- Q8_0 quant: ~8.9GB VRAM
- BF16 full precision: ~17GB VRAM
- Full 1M context: 24GB+ VRAM needed for KV cache (otherwise CPU offload or reduce context)
Discussion notes:
- One commenter questioned if this violates ToS (using “Mythos” access / Claude synthetic data)
- Rare combination of long-context + high-quality reasoning in open-source 9B class