MiLMMT-46-1B-v0.1 — MLX 6-bit
Apple MLX weights for
xiaomi-research/MiLMMT-46-1B-v0.1,
Xiaomi's 46-language translation model (a translation fine-tune of Gemma 3 1B).
| |
|---|
| Quantization | 6-bit, --q-bits 6 (6.501 bits per weight as reported by the converter) |
| Size on disk | 1.0 GB |
| Runtime | mlx-lm / mlx-swift-lm |
model_type | gemma3_text |
This is the MLX build to use. The
4-bit sibling
is 269 MB smaller but visibly degraded — see below.
Why 6-bit and not 4-bit
Naive 4-bit post-training quantization measurably damages this model. Every
regression it introduces disappears at 6 bits, with no calibration step of any
kind. Both builds were run on the same 16-sentence JA↔EN set, on the same
machine, with a byte-identical prompt and greedy decoding, so the difference is
attributable to the quantization rather than to the harness:
| Source | 4-bit | 6-bit |
|---|
| 来年度の予算編成 | "fiscal 2022" — hallucinated year | "next fiscal year's budget" |
| のぞみ1号 (JA→EN) | "the Shinkansen" — train name lost | "Nozomi 1" |
| "I hope this message finds you well" | 「今週のご挨拶」— nonsense | 「…心よりお祈り申し上げます」 |
| "Nozomi No. 1" (EN→JA) | 「ノズミ1号」— misspelt | 「ノゾミ1号」 |
Small models are disproportionately sensitive to naive PTQ. Calibrated
quantization (mlx_lm.dwq, mlx_lm.awq) might reach this quality at 4-bit
size, but was not needed to fix the regressions and is untried here.
Versus the GGUF
At equal size, this build is competitive with
penta2himajin/MiLMMT-46-1B-v0.1-Q4_K_M-GGUF
on quality and throughput, and loses on cold load — MLX has no mmap equivalent,
so it pays for the whole file on every load. Timings are from a battery-powered
run; read them as ratios, not absolutes.
| MLX 6-bit | GGUF Q4_K_M |
|---|
| Disk | 1.0 GB | 1.01 GB |
| Cold load | 1546 ms | 366 ms |
| p50 latency | 251 ms | 248 ms |
| Throughput | 204 chars/s | 215 chars/s |
On quality the two trade places sentence by sentence. One example where this
build is the better of the two: "The cabinet approved the basic policy…" renders
as 「内閣は…承認した」here, against the GGUF's ungrammatical 「閣議決定は…承認した」.
Pick MLX if you are already on an MLX stack; pick the GGUF if cold load matters
(an app that evicts weights between uses, for instance).
Prompt format
MiLMMT ships no chat template. Do not apply one — prompt it raw, exactly as
the upstream model card specifies:
1Translate this from <source language name> to <target language name>:
2<source language name>: <source sentence>
3<target language name>:
Use the language names from the upstream card's supported-language list
(e.g. Japanese, English). Recommended decoding: top_k=1, temperature=0.
1pip install mlx-lm
2PROMPT=$'Translate this from Japanese to English:\nJapanese: こんにちは、今日も一日頑張りましょう。\nEnglish:'
3mlx_lm.generate --model penta2himajin/MiLMMT-46-1B-v0.1-6bit \
4 --prompt "$PROMPT" --max-tokens 128 --temp 0.0
Because there is no turn marker, generation can run on into a second
translation block. Stop on the string Translate this from, or trim at it.
Conversion
1mlx_lm.convert --hf-path xiaomi-research/MiLMMT-46-1B-v0.1 \
2 -q --q-bits 6 --mlx-path MiLMMT-46-1B-v0.1-6bit
Converted with mlx-lm 0.31.3.
License
Gemma Terms of Use, inherited from the base model —
not Apache 2.0.
MiLMMT-46-1B is derived from Gemma 3, so redistribution and use are governed by
the
Gemma Terms and the
Gemma Prohibited Use Policy,
which pass through to anyone who obtains these weights.
Citation
1@misc{shang2026scalingmodeldatamultilingual,
2 title={Scaling Model and Data for Multilingual Machine Translation with Open Large Language Models},
3 author={Yuzhe Shang and Pengzhi Gao and Wei Liu and Jian Luan and Jinsong Su},
4 year={2026},
5 eprint={2602.11961},
6 archivePrefix={arXiv},
7 url={https://arxiv.org/abs/2602.11961},
8}