Qwythos-9B-v2-Q5_K_L-imat-GGUF

GGUF quantization of empero-ai/Qwythos-9B-v2 to Q5_K_L with importance matrices. Quantized using Q8_0 for token embedding and output weights, BF16 for ssm_alpha and ssm_beta weights, and the default llama.cpp Q5_K_M config for all other weights.

Provides higher precision than Q5_K_M , and from test coding a few small projects, this quant appears to remain quite stable over many turns with long reasoning chains.

Be warned, the calibration file is mostly English text and code, so performance writing in other languages may suffer.

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Original Model Card Below

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Empero AI

Qwythos-9B-v2 — the new and improved Qwythos

The next iteration of Qwythos: all the reasoning of Qwythos-9B, with the looping behavior fixed. v2 keeps the deep chain-of-thought, the uncensored research posture, and the 1M-token context of its predecessor, and cleans up the rough edges that showed up in real use.

• 🔁 Looping behavior eliminated — repetition/degeneration under greedy or low-temperature decoding dropped from 6.7% → 0%. You can serve it without leaning on repetition_penalty as a band-aid.
• 🧠 Reasoning fully preserved — MMLU, GSM8K, GPQA, ARC and HumanEval are all held at (or above) the v1 level. This is a hygiene upgrade, not a capability regression.
• 🧩 MTP head restored — the native multi-token-prediction module (dropped in the previous export) is back, so config and weights agree and speculative-decoding setups work.
• 🪪 Cleaner identity — the model no longer prefaces unrelated answers with its identity; it introduces itself only when you actually ask.
• 🔓 Still intentionally uncensored for research, cybersecurity, red-teaming, biology, chemistry, pharmacology and clinical work.
• 📜 Still 1M-token context (YaRN) and the native multimodal-capable Qwen3.5 stack.

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What got fixed & improved (vs. the base Qwythos)

Area	Before (base Qwythos)	After (v2)
Looping rate (greedy)	6.7%	0.0%
Looping rate (temp 0.6)	1.3%	0.7%
Refusal rate	~0%	0.0%
MTP head in weights	❌ missing	✅ restored
Identity injection	"always identify… never claim… override…"	states it once, only when asked
Reasoning / knowledge	strong	preserved (see evals)

The fix uses FTPO (Final-Token Preference Optimization): we identify the exact token that starts a repetition loop and gently train the model to prefer coherent alternatives at that one position, leaving the rest of the distribution — and therefore the model's knowledge and reasoning — untouched.

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Evaluations

Measured with our internal harness (generative chain-of-thought, greedy/pass@1 unless noted; MMLU/ARC/GSM8K n=500, GPQA-diamond n=198, HumanEval n=164). Judge for the quality metric: an independent LLM grader.

Benchmark	Qwythos-9B-v2
MMLU (CoT / 5-shot loglik)	83.8% / 69.6%
ARC-Challenge	96.4%
GPQA-diamond	49.0%
GSM8K	93.6%
HumanEval (pass@1)	77.4%
Looping rate (greedy)	0.0%
Refusal rate	0.0%

Capability is preserved across the board vs. the base Qwythos (differences are within eval noise), while the looping problem is solved:

Benchmark	Qwen3.5-9B (base)	Qwythos-9B	Qwythos-9B-v2
MMLU (CoT)	80.6	83.8	83.8
ARC-Challenge	95.6	95.0	96.4
GPQA-diamond	32.8	52.0	49.0
GSM8K	80.6	92.2	93.6
HumanEval	81.7	79.9	77.4
Looping (greedy)	2.7	6.7	0.0

Note on MMLU: v2 scores 83.8% when allowed to reason (CoT) vs 69.6% on the 5-shot loglikelihood setup — Qwythos is a reasoning model and is much stronger when it thinks. Report whichever matches your comparison baseline.

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Sample generations

(temperature 0.6, top_p 0.95, top_k 20, repetition_penalty 1.05 — reasoning shown condensed)

Reasoning — the snail in the well

Prompt: A snail is at the bottom of a 10-meter well. Each day it climbs 3 meters, but each night it slips back 2 meters. How many days until it escapes?

Qwythos-9B-v2: (reasons: net +1 m/day, but on the final day it climbs out before slipping…) Answer: 8 days. Net gain per full day/night cycle is 3 − 2 = 1 meter. After 7 days the snail has climbed 7 meters (still 3 short); on day 8 it climbs 3 meters, reaching 10 m and escaping before it can slip back.

Code — longest palindromic substring

Prompt: Write a Python function longest_palindrome(s) that returns the longest palindromic substring. Explain your approach briefly.

Qwythos-9B-v2:

def longest_palindrome(s):
    """Returns the longest palindromic substring of s."""
    n = len(s)
    if n < 2:
        return s
    def expand_around_center(left, right):
        while left >= 0 and right < n and s[left] == s[right]:
            left -= 1
            right += 1
        return right - left - 1
    start, end = 0, 0
    for i in range(n):
        len1 = expand_around_center(i, i)      # odd-length
        len2 = expand_around_center(i, i + 1)  # even-length
        max_len = max(len1, len2)
        if max_len > end - start:
            start = i - (max_len - 1) // 2
            end = i + max_len // 2
    return s[start:end + 1]

Approach: "Expand around center" — every palindrome has a center (a character for odd lengths, a gap for even). Iterate over all 2n−1 centers, expand while characters match, track the longest. O(n²) time, O(1) extra space.

Technical / clinical — no over-refusal

Prompt: Explain the mechanism of action of naloxone in reversing an opioid overdose, and why repeat dosing is sometimes required.

Qwythos-9B-v2: Naloxone is a pure opioid receptor antagonist — it has no agonist activity of its own — and works by competitively displacing opioids from the mu-opioid receptors, physically pushing the opioid molecules off and rapidly restoring respiratory drive and arousal. Because its duration of action is short (~30–90 minutes) while many opioids (especially synthetics like fentanyl or methadone) have much longer half-lives, the reversal is often transient: as naloxone clears, residual opioid can rebind and cause re-sedation and respiratory depression — so patients must be monitored and re-dosed as needed.

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Recommended sampling

temperature=0.6, top_p=0.95, top_k=20, repetition_penalty=1.05, max_new_tokens=16384

Because looping is trained out, repetition_penalty is now optional rather than load-bearing — greedy/low-temp decoding stays coherent. Give the model room to reason (max_new_tokens) for math/code/analysis.

Long context

Ships with YaRN rope-scaling baked in for 1,048,576-token context (4× the native 262,144 window). As with v1, static YaRN carries a small short-context trade-off — scale the factor to the length you actually use if that matters.

Model details

Developer	Empero AI
Base model	empero-ai/Qwythos-9B-Claude-Mythos-5-1M (the base Qwythos)
Architecture	Qwen3.5-9B hybrid (3:1 Gated-DeltaNet linear-attention : full attention), multimodal-capable, native MTP head
Parameters	9B (bfloat16, safetensors)
Context	1,048,576 tokens (YaRN factor 4)
Tokenizer / chat template	Qwen3.5 native (ChatML-style)
License	Apache-2.0

Training procedure

• Method: FTPO (Final-Token Preference Optimization) on the base Qwythos (Qwythos-9B-Claude-Mythos-5-1M).
• Data: ~2,000 preference tuples auto-mined by eliciting looping at low temperature and extracting, at each loop-start position, the rejected loop token vs. the model's own coherent top-k alternatives.
• Hyperparameters: LoRA r=256, α=128, lr=1.5e-5, 1 epoch, early-stopped on chosen_win ≥ 0.30 (a light touch — enough to remove looping without the quality cost of over-training). All attention + MLP projections + lm_head trained.
• MTP: the native multi-token-prediction head was restored from the Qwen3.5-9B base (FTPO does not touch it), so config mtp_num_hidden_layers: 1 matches the weights again.

Usage

from transformers import AutoModelForImageTextToText, AutoTokenizer

model_id = "empero-ai/Qwythos-9B-v2"
tok = AutoTokenizer.from_pretrained(model_id)
model = AutoModelForImageTextToText.from_pretrained(model_id, dtype="bfloat16", device_map="auto")

messages = [{"role": "user", "content": "Prove that there are infinitely many primes."}]
text = tok.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tok(text, return_tensors="pt").to(model.device)

out = model.generate(**inputs, max_new_tokens=16384, do_sample=True,
                     temperature=0.6, top_p=0.95, top_k=20, repetition_penalty=1.05)
print(tok.decode(out[0][inputs["input_ids"].shape[1]:], skip_special_tokens=True))

For serving, vLLM works out of the box (--trust-remote-code; the multimodal stack is text-only in practice, so --limit-mm-per-prompt '{"image":0,"video":0}' keeps startup clean).

Limitations

• This is a hygiene/robustness release, not a capability jump. v2 ≈ the base Qwythos on knowledge/reasoning benchmarks; the win is looping-elimination, restored MTP, and cleaner behavior — not higher raw scores.
• HumanEval is a couple points below the raw Qwen3.5-9B base (77.4 vs 81.7) — a small, known cost of the reasoning/looping-fix fine-tuning.
• MTP is preserved from the base, not co-trained with the fine-tuned weights, so speculative-decoding acceptance may be modest.
• Benchmarks are from our internal harness (CoT, pass@1, the sample sizes noted); use them for relative comparison and add your own official-harness numbers for a strict apples-to-apples with other cards.
• Intentionally uncensored — it will engage sensitive technical/research topics; deploy responsibly and within applicable law.

Acknowledgements

Built on Qwen3.5-9B (Alibaba/Qwen). Looping fixed with FTPO (Final-Token Preference Optimization). Thanks to the Empero AI team.