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Open-weight model · Image and text to text

Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4

by Ethan Todd ethantodd4l/Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4

Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 is an open-weight model for image and text to text from Ethan Todd, released under other. It has 15.6B parameters and a 262,144-token context. At 16-bit it needs about 37.5 GB of GPU memory, which fits on 1x MI300X from $1.85 an hour, at the lowest prices in the SAVRN Index. It draws 24 downloads a month.

quantized to OCP MXFP4 4-bit weights in the same Quark checkpoint container as The weights are plain RTN, not AWQ: see the note below. The 15 MTP tensors are kept in BF16; the radiance runtime loads them with RADIANCEQUARKBF16MTP=1. Why RTN instead of AWQ.

Parameters15.6B
Context262,144
Weights19.8 GB
Licenseother
AccessOpen weights
Monthly Downloads24

Runs On

What it takes to serve Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 (15.6B 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 31.2 GB 37.5 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
8-bit 15.6 GB 18.7 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
4-bit 7.8 GB 9.4 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 7, 2026.

Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 on every accelerator the SAVRN Index prices, at every precision

Model Card

quantized to OCP MXFP4 4-bit weights in the same Quark checkpoint container as The weights are plain RTN, not AWQ: see the note below. The 15 MTP tensors are kept in BF16; the radiance runtime loads them with RADIANCEQUARKBF16MTP=1. Why RTN instead of AWQ. The first build of this checkpoint used AWQ with the same smoothing recipe as AMD's release. The AWQ fold itself was mathematically consistent, but on this model a few layers converged to weights to 32-element MXFP4 blocks then destroyed those layers on real, outlier-carrying inputs (layer 7 output relative error ~324), and repairing the worst layers individually was not enough; the remaining smoothed layers still accumulated too much…

Excerpt from the card by Ethan Todd, licensed other.

Configuration

Architecture
Qwen3_5ForConditionalGeneration
Context length (tokens)
262,144
Layers
64
Hidden size
5,120
Feed-forward size
17,408
Attention heads
24
Key/value heads
4
Head dimension
256
Vocabulary size
248,320
Model type
qwen3_5
Quantization
quark

Identity and Version

Repository
ethantodd4l/Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4
Publisher
Ethan Todd
Task
Image and text to text
Modality
Image and text
Library
transformers
Parameters
15.6B parameters
Languages
Not stated by the source
Revision
3cd117e0d4b1499324bf92479cf2ca30b463041e
First published
2026-10-03
Last updated
2026-10-04

Files and Weights

14 files, 19.8 GB in total. The weights are 1 file totalling 19.8 GB in safetensors.

Weights1 file · 19.8 GB
Configuration4 files · 12.0 KB
Tokenizer4 files · 22.9 MB
Documentation3 files · 21.9 KB
Other1 file · 9.0 KB
Repository1 file · 1.7 KB
Every file
FileTypeSizeSHA-256
model.safetensorsWeights19.8 GB 74b8f551511d
config.jsonConfiguration11.0 KB —
generation_config.jsonConfiguration214 B —
preprocessor_config.jsonConfiguration390 B —
video_preprocessor_config.jsonConfiguration385 B —
LICENSEDocumentation13.3 KB —
NOTICEDocumentation1.5 KB —
README.mdDocumentation7.0 KB —
chat_template.jinjaOther9.0 KB —
.gitattributesRepository1.7 KB —
merges.txtTokenizer3.4 MB —
tokenizer.jsonTokenizer12.8 MB 0997f410c57a
tokenizer_config.jsonTokenizer17.9 KB —
vocab.jsonTokenizer6.7 MB —

License and Download

License
other
Access
Open weights, no gate
Download size
19.8 GB
Download from Ethan Todd

Released by Ethan Todd through its official repository on Hugging Face. Read the license.

Built From

  • Derived from ukisai/Swift-1.5-Qwen3.8-27b
  • Quantized from ukisai/Swift-1.5-Qwen3.8-27b

Memory Requirements

PrecisionWeights in memory
As published19.8 GB
16-bit31.2 GB
8-bit15.6 GB
4-bit7.8 GB

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

Questions About Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4

How much GPU memory does Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 need?

About 37.5 GB at 16-bit and 9.4 GB at 4-bit: the weights (15.6B parameters) plus a working margin. A long context needs more.

What is the cheapest GPU to run Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 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.

What license is Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4 released under?

other, as its publisher declares it. Read the license text before commercial use.

What is Swift-1.5-Qwen3.8-27b-Quark-RTN-MXFP4's context length?

262,144 tokens, from the maximum position embeddings in its published configuration.

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