AX-Qwen3.8-2.4T-A95B-MLX-AXQ-2bit-MTP
Experimental AXQ 2-bit MLX pack of
Qwen/Qwen3.8-2.4T-A95B-FP8.
Not certified. Will not be certified in this revision. Layer-stack SSD expert paging is too slow for practical serving, so this pack is a hobby / curiosity artifact: a 2.4T-class Qwen MoE that can exist on a Mac only because experts are paged from disk. If that sounds fun, enjoy. If you need something you can actually work with, use a smaller certified AXQ pack (Qwen 3.6, Flash, Coder-Next, GPT-OSS). No AXQ 4-bit sibling will be published for this base.
This card is convert evidence, not a quality or speed claim. Quality vs BF16 / FP8 was not measured.
This is an AXQuant pack (qwen38-moe-v1), not mlx-optiq. Do not load
the OptiQ Qwen 3.8 repos in AX Engine.
Full convert notes: docs/qwen38-axq-2bit.md.
Why it is slow
The full table is ~1.13 TiB. No shipping Mac can resident-load it
(512 GB unified memory is still too small). AX Engine pages one fused
expert layer at a time (ax_expert_stream.json, required=true). Every
token waits on SSD I/O for routed experts. That is why this revision is
not a product path.
Estimated streamed peak: ~56 GiB resident trunk + ~12 GiB one layer + KV
(about 100 GiB with headroom). You still need
AX_ENGINE_2BIT_EXPERIMENTAL=1.
Do not mlx_lm.load this pack as a fully resident model.
Recipe
Affine, group size 32
(qwen38-experimental-2bit-v0.1.yaml):
| Role | Bits |
|---|---|
| Expert, attention, shared MLP | 2 |
Embedding, router (mlp.gate) | 8 |
| Norms, LM head | 16 (BF16) |
| MTP | 16, byte-preserved into mtp.safetensors |
Source: official FP8 revision d2dc35658bcf77e66643428cb52e774cc3b5bd29
(128×128 weight_scale_inv, unfused per-expert tensors). Convert uses the
AXQuant stream backend because mlx_lm.load cannot ingest that snapshot.
Measured artifact
From axquant_manifest.json after weight verification (2026-08-13):
| Quantity | Value |
|---|---|
| Plan effective BPW | 3.157 |
| Measured total BPW | 4.074 |
| Measured main BPW | 4.030 |
| Logical parameters | 2,446,182,725,504 |
| Weight files | 1,245,853,341,088 bytes (1.13 TiB) |
| MTP sidecar | 26,989,794,744 bytes |
| Hub budget class | 2bit (leaf). Recipe class remains 2bit-experimental. |
| Product class | 2bit-experimental |
Stream contract: 512 experts, 10 per token, 828 streamed tensors, layer-stack
mode. Converted model_type is qwen3_5_moe (92 hybrid-attention layers,
hidden 8192, MoE intermediate 2048, one MTP layer).
Status
| Item | Status |
|---|---|
Convert + ax_expert_stream.json | Done on df-macstudio-m2 |
| Hub weights | Uploaded |
| Quality vs BF16 / FP8 | Not measured |
| AX Engine cert | Will not certify this revision (too slow to be practical) |
| MTP present | True (native mtp.safetensors sidecar, ~27 GiB) |
| MTP acceleration | Not claimed |
Hobby use only. Not a supported product pack.