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Open-weight model · Text classification

Zircon-0.6B-v2-mlx

by Fahrenheit Research FahrenheitResearch/Zircon-0.6B-v2-mlx

Zircon-0.6B-v2-mlx is an open-weight model for text classification from Fahrenheit Research, released under Apache License 2.0. It has 596M parameters and a 40,960-token context. At 16-bit it needs about 1.4 GB of GPU memory, which fits on 1x MI300X from $1.85 an hour, at the lowest prices in the SAVRN Index.

Zircon v2 is a 0.6B-parameter decision model from Fahrenheit Research. It runs fully on-device on Apple silicon.

Parameters596M
Context40,960
Weights633.4 MB
Licenseapache-2.0
AccessOpen weights
Monthly Downloads—

Runs On

What it takes to serve Zircon-0.6B-v2-mlx (596M parameters): the memory its weights need at each precision, and the cheapest way to rent enough data-center GPUs to hold them.

PrecisionWeightsMemory neededCheapest setupPer hourAlso fits
16-bit 1.2 GB 1.4 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
8-bit 0.6 GB 0.7 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
4-bit 0.3 GB 0.4 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00

Memory is the weights at that precision plus 20% for the runtime and a short context; a long context needs more. Prices are the lowest on-demand hourly rates in the SAVRN Index, read Oct 1, 2026.

Zircon-0.6B-v2-mlx on every accelerator the SAVRN Index prices, at every precision

Model Card

By Fahrenheit Research, published under apache-2.0, revision e9071a690bb2.

Zircon v2 is a 0.6B-parameter decision model from Fahrenheit Research. It runs fully on-device on Apple silicon. You give it an email, a message or a pending task plus a set of options, and it returns a calibrated probability for each option in under 50 ms per decision. (1) MacBook Pro (Apple M5), 8-bit weights, median. Speed varies by hardware. (2) Fahrenheit Research internal testing, September 2026, on held-out emails not seen in training. (3) Fahrenheit Research internal testing, September 2026. 400 cases (2,000 decisions) from the public LocalLLaMA typed-decisions test set. (4) Fahrenheit Research internal testing, September 2026, on game seeds not seen in training. Built on Qwen3-0.6B…

Read Fahrenheit Research's full model card

Zircon v2

Zircon v2 is a 0.6B-parameter decision model from Fahrenheit Research. It runs fully on-device on Apple silicon. You give it an email, a message or a pending task plus a set of options, and it returns a calibrated probability for each option in under 50 ms per decision.

Specifications

Version Zircon v2 (0.6B, MLX 8-bit)
Released September 2026
Parameters 0.6 billion
Model size about 634 MB
Runtime Apple silicon via MLX, runs locally
Output One probability per option
Decision types Pick one, yes or no, score on a scale
Response time 30 to 45 ms per decision (1)

Email and message triage (2)

Task Accuracy
What to do: reply, escalate, archive, or mark as spam 93%
Notify now or hold 100%
Priority on a 4-level scale 94%
Pending steps: execute, hold for a reference, defer, or escalate 100%

Typed-decisions benchmark (3)

Metric Zircon v2
Accuracy 77%
Brier score (lower is better) 0.060

Games (4)

Game Moves matching the expert
Tetris 80%
Snake 78%

(1) MacBook Pro (Apple M5), 8-bit weights, median. Speed varies by hardware. (2) Fahrenheit Research internal testing, September 2026, on held-out emails not seen in training. (3) Fahrenheit Research internal testing, September 2026. 400 cases (2,000 decisions) from the public LocalLLaMA typed-decisions test set. (4) Fahrenheit Research internal testing, September 2026, on game seeds not seen in training.

Built on Qwen3-0.6B (Apache 2.0). By Fahrenheit Research.

Configuration

Architecture
Qwen3ForCausalLM
Context length (tokens)
40,960
Layers
28
Hidden size
1,024
Feed-forward size
3,072
Attention heads
16
Key/value heads
8
Head dimension
128
Vocabulary size
151,936
RoPE base
1,000,000
Stored precision
bfloat16
Model type
qwen3

Identity and Version

Repository
FahrenheitResearch/Zircon-0.6B-v2-mlx
Publisher
Fahrenheit Research
Task
Text classification
Modality
Text
Library
mlx
Parameters
596M parameters
Languages
en
Revision
e9071a690bb2855bd51e728d5cd8b60c3cf9e965
First published
2026-09-25
Last updated
2026-09-26

Files and Weights

11 files, 644.9 MB in total. The weights are 1 file totalling 633.4 MB in safetensors.

Weights1 file · 633.4 MB
Configuration5 files · 52.8 KB
Tokenizer2 files · 11.4 MB
Documentation1 file · 1.9 KB
Other1 file · 4.2 KB
Repository1 file · 1.6 KB
Every file
FileTypeSizeSHA-256
model.safetensorsWeights633.4 MB f22f54017e50
alphabet.jsonConfiguration1.5 KB —
calibration.jsonConfiguration246 B —
config.jsonConfiguration1.0 KB —
generation_config.jsonConfiguration239 B —
model.safetensors.index.jsonConfiguration49.8 KB —
README.mdDocumentation1.9 KB —
chat_template.jinjaOther4.2 KB —
.gitattributesRepository1.6 KB —
tokenizer.jsonTokenizer11.4 MB be75606093db
tokenizer_config.jsonTokenizer729 B —

License and Download

License
apache-2.0
Access
Open weights, no gate
Download size
633.4 MB
Download from Fahrenheit Research

Released by Fahrenheit Research through its official repository on Hugging Face. Read the license.

Built From

Memory Requirements

PrecisionWeights in memory
As published633.4 MB
16-bit1.2 GB
8-bit0.6 GB
4-bit0.3 GB

Weights only, from the published parameter count; the key-value cache and runtime add to this.

Questions About Zircon-0.6B-v2-mlx

How much GPU memory does Zircon-0.6B-v2-mlx need?

About 1.4 GB at 16-bit and 0.4 GB at 4-bit: the weights (596M parameters) plus a working margin. A long context needs more.

What is the cheapest GPU to run Zircon-0.6B-v2-mlx on?

At 16-bit, 1x MI300X from $1.85 an hour; at 4-bit, 1x MI300X from $1.85 an hour, at the lowest on-demand prices the SAVRN Index lists.

Can I use Zircon-0.6B-v2-mlx commercially?

Yes. Zircon-0.6B-v2-mlx is released under Apache License 2.0. The Apache License 2.0 is a permissive open-source license. It permits commercial use, modification and redistribution. It requires keeping the license and copyright notices and any NOTICE file, stating significant changes, and it includes an express patent grant from contributors.

What is Zircon-0.6B-v2-mlx's context length?

40,960 tokens, from the maximum position embeddings in its published configuration.

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