Qwen3.8-Flash-Next MLX 4-bit
Local MLX conversion of Qwen/Qwen3.8-Flash-Next.
- Language weights: affine 4-bit, group size 64.
- PLE n-gram embedding: affine 4-bit, group size 32.
- MoE routing gates: affine 8-bit, group size 64.
- Vision tower: BF16.
- Native MTP tensors are not included in this base checkpoint.
This model requires the Qwen4-Exp support in the accompanying local
mlx-vlm checkout.
Runtime setup
Qwen4-Exp is newer than the current stock mlx-vlm model registry. Until the
implementation is upstreamed, use the runtime module bundled in this repo:
git clone https://github.com/Blaizzy/mlx-vlm.git
cp -R mlx_vlm_qwen4_exp/qwen4_exp mlx-vlm/mlx_vlm/models/qwen4_exp
python3 -m venv .venv
.venv/bin/pip install -e ./mlx-vlm
.venv/bin/pip install --upgrade git+https://github.com/huggingface/transformers.git
.venv/bin/mlx_vlm.generate \
--model . \
--prompt "Hello!" \
--max-tokens 256
The bundled module registers the Qwen3-VL-compatible processor and multimodal chat format automatically. Native MTP speculative decoding is not included.
For an interactive terminal chat after setup:
.venv/bin/mlx_vlm.chat \
--model . \
--max-tokens 512 \
--temperature 0.0
Commands inside the chat include /image <path>, /clear, and /exit.
LM Studio (experimental)
LM Studio's current MLX runtime does not yet bundle qwen4_exp. From this
model directory, install the included compatibility module:
chmod +x install_lmstudio_patch.sh
./install_lmstudio_patch.sh
Then unload and reload the model in LM Studio. On a 128 GB Mac, LM Studio may still reject the checkpoint based on its conservative memory estimate. Enable Developer Mode and select Settings → Hardware → Model loading guardrails → OFF only after closing other memory-heavy applications. The measured peak is about 104.1 GB, so smaller-memory Macs are not recommended.
Verified with LM Studio 0.4.21 (Build 2), MLX runtime 1.11.0, including
multi-turn text chat and image understanding. The compatibility module also
supplies the sparse-attention path needed by larger image prompts. Updating LM
Studio's MLX runtime may replace the installed module; rerun the script if
qwen4_exp becomes unrecognized again or vision generation fails after an
update.
Verified locally
Tested on a 128 GB Apple M5 Max:
- Text: 9.13 prompt tokens/s, 60.95 generation tokens/s.
- Image + text: 214.84 prompt tokens/s, 48.92 generation tokens/s.
- Peak unified memory: 104.07 GB.
- LM Studio multi-turn text chat: 36.63 generation tokens/s.
- LM Studio image understanding: 31.01 generation tokens/s.