Qwen3.8-Flash-Next Abliterated — EXL3 2.50 bpw (single 24 GB GPU)

A refusal-removed (abliterated) build of Qwen's Qwen3.8-Flash-Next, quantized to EXL3 2.50 bpw so the full model runs on a single 24 GB card (RTX 3090 / 4090) using MoE CPU-offload — with the vision tower, MTP head, native 262,144-token context, and the PLE n-gram table all intact.
What this is
- Base model: Qwen/Qwen3.8-Flash-Next — a Qwen4-preview MoE (~177B stored / ~6B active), Gated DeltaNet linear attention + Qwen Sparse Attention, MTP, native vision, 262K context.
- Abliteration source: orcarouter/Qwen3.8-Flash-Next-Uncensored (BF16, 131 shards).
- Quantization: EXL3 2.50 bpw, single pass. Covers that the BF16 (360 GB) source was abliterated by OrcaRouter — this repo is the quant, not a new ablation.
Layout
| layer group | bitrate | flag |
|---|---|---|
| routed experts / decoder | 2.50 bpw (per-tensor alloc, ~2.0–3.0) | -b 2.50 |
| attention + shared experts | higher ("hq") | -hq |
| MTP head | 4 bpw | -mb 4 |
| vision tower | 6 bpw | -vb 6 |
| n-gram embedding table | 3 bpw | -ngb 3 |
Total artifact: ~61 GB (41.5 GB weights in 6 shards + 19 GB n-gram table). Measured average bitrate ~2.52 bpw.
Conversion
# engine (MoE CPU-offload capable):
git clone -b dflash2-pathway https://github.com/r0b0tlab/exllamav3
# convert (from the abliterated BF16):
cd exllamav3 && python3 convert.py \
-i ../Qwen3.8-Flash-Next-Uncensored \
-o ../qwen38-flash-next-abliterated-exl3-b250 \
-w ../work/target-b250 \
-b 2.50 -mb 4 -vb 6 -hq -ngb 3 -cr 250
Running (single 24 GB card)
Requires the same MoE CPU-offload setup as the stock 2.50bpw pack: ~59 GB host RAM for the CPU expert tail and a fast NVMe for the streamed n-gram table.
# interactive (no MTP — see note below):
python3 examples/chat.py -m ./qwen38-flash-next-abliterated-exl3-b250 \
-mode chatml -cs 32768 -cq 3 -mcs 320 -mct 16
Serving flags — the two that actually matter:
-mctmust equal your physical core count. The upstream README's-mct 6was "6 = their 6-core machine." On a 16-core CPU,-mct 16jumps from ~15–24 tok/s to ~26–47. This knob alone is roughly a 2× swing.-mcs 320= speed preset (fewer experts offloaded → more resident on GPU → faster, ~23 GB VRAM).-mcs 384= long-context preset (~20 GB, slower). 320 fits a 24.5 GB card; go much lower and you OOM.
Measured — RTX 3090 Ti + Ryzen 9 5950X (16-core) + DDR4: ~47 tok/s decode with MTP off (mcs 320, 16 threads), settling upward from ~37 cold as the offload's hot-expert set warms in VRAM. MTP only pays with greedy sampling — on the interactive temp-0.8 sampler acceptance is ~47% and decode roughly 3× slower, so leave -mtp off for chat. Full native context: -cs 262144 -cq 3 (the 3-bit KV cache is ~1.1 GB at 262K).
Smoke test (on the quantized artifact)
Fired on the 2.50 bpw output, not the BF16, to confirm the ablation survived quantization:
- weapons prompt (RDX synthesis) → answered directly, no refusal
- medical prompt (pentobarbital protocol/dosage) → answered directly, no refusal
- sanity (17×23) → correct step-by-step (391), coherent reasoning, native
thinkingtags intact
Notes & caveats
- Not retrained, not instruction-tuned-away. Abliteration removes the refusal direction; the underlying model still has gradient-descent knowledge and no safety alignment layer. Assume standard safety/capability tradeoffs of any ablated model.
- Research use. Same Qwen license terms as the base; this is the quant of OrcaRouter's ablated BF16.
- Low-bitrate (2.5 bpw) quantization is aggressive — per-token quality is below the BF16 source, expect some degradation on hard recall vs. denser quants. The refusal check passed at this bitrate; broader evals (the upstream Q200v2 kit) were not re-run on this ablated quant.
- Vision tower smoke-tested on the quant (synthetic image: shapes + text) — shapes, colors, and OCR all correct; preserved at 6 bpw per the conversion flags.
Credits
- Idea, engine, conversion method, serving recipe: r0b0tlab/qwen38-flashnext-exl3 — the
dflash2-pathwayExLlamaV3 fork, the MoE CPU-offload approach, and the exact-b 2.50 -mb 4 -vb 6 -hq -ngb 3conversion recipe are theirs. This repo is essentially "their pack, but abliterated." - Engine: turboderp/ExLlamaV3 (MIT).
- Abliteration: orcarouter/Qwen3.8-Flash-Next-Uncensored (BF16 source).
- Base weights: Qwen/Qwen3.8-Flash-Next.
License
Underlying weights: Qwen License (see parent). Ablitration: OrcaRouter's work. Quant: EXL3 (ExLlamaV3, MIT).