Qwen3-30B-A3B — Topiary w576 (code calibration)
A
Topiary checkpoint: the routed experts of
Qwen/Qwen3-30B-A3B sculpted by
routed activation salience, truncated to their top-576 of 768 intermediate
neurons (−25% expert width), then quantized to 4-bit (group size 64). Calibrated
on
code — this is the coding-slanted sibling of the mixed-calibration w640;
smaller, sharper on code, weaker on math.
Standard mlx-lm checkpoint — loads with stock mlx-lm, no custom code:
1pip install mlx-lm
2mlx_lm.generate --model jesusluque/qwen3-30b-topiary-w576-code --prompt "..."
The equal-bytes head-to-head that motivated Topiary
At the same memory budget, against the community 3-bit quantization:
| Checkpoint | GB | Code PPL ↓ | WikiText PPL ↓ |
|---|
| This model (w576-fine, 4-bit) | 13.10 | 2.87 | 12.98 |
| Community 3-bit, full width | 13.36 | 3.26 | 15.70 |
| Mixed 3–4-bit | 14.00 | 3.07 | 13.38 |
Calibrated on code, it still wins general text by −17% PPL. Other signals:
HumanEval 84%, GSM8K 78%, MMLU 64%, ARC 43%, HellaSwag 60%, ~55 tok/s decode.
Honest limit: the code-only calibration trades math away (GSM8K 78% vs 94%
of the mixed-calibration w640 sibling). The calibration corpus is an
amplitude-vs-specialization dial — choose the sibling that matches your use.
Calibration
Code corpus (The Stack: Python + C++ + Swift), routed-only statistics
(salience accumulated only over tokens the router sends to each expert).
Provenance
- Base: Qwen/Qwen3-30B-A3B (Apache-2.0)
- Build: neuron-granularity permutation of the original bf16 experts, truncation
to k=576 of 768, then 4-bit g64 quantization.
- All numbers reproducible from frozen configs; greedy decoding, fixed seeds.
Update (Aug 2026): pruning costs knowledge — measured on the taper sibling
The taper flagship of this family was compared against the UNPRUNED
Qwen3-30B-A3B-4bit on a four-benchmark suite (n=500 on MMLU/LAMBADA):
reasoning intact (MATH-500/MBPP), but -10 MMLU / -4.4 LAMBADA points —
salience pruning removes knowledge, not reasoning. This model shares the
pruning method and was NOT re-measured on that suite; expect a knowledge
cost of similar nature. If broad world knowledge dominates your workload,
prefer the unpruned checkpoint. Details:
github.com/jesusluque/topiary-stream (paper §2.4).