This repository contains a DMX-encoded delta for Qwen2.5-3B-Instruct, enabling near-lossless reconstruction of the full model from a compatible base checkpoint.
DMX reduces storage requirements by 55-80% while preserving model quality (+0.03-0.16% perplexity), using structure-aware integer transformations rather than generic byte-level compression.
Unlike traditional compression, DMX operates at the model level — storing structured weight deltas that can be deterministically reconstructed. This enables efficient distribution and versioning of model variants without duplicating full checkpoints.
DMX extends delta compression into a system for managing model evolution, with support for efficient chaining and adaptive rebasing to maintain high compression efficiency across model families.
1python -c "
2from transformers import AutoModelForCausalLM
3from safetensors.torch import save_file
4import torch
5
6m = AutoModelForCausalLM.from_pretrained('Qwen/Qwen2.5-3B', torch_dtype=torch.float32)
7save_file({k: v.clone() for k, v in m.state_dict().items()}, 'qwen2.5-3b-base.safetensors')
8"
1# Download the delta (2.9 GB instead of 13.6 GB)
2huggingface-cli download Senat1/dmx-qwen2.5-3b-instruct-delta instruct.dmxd
3
4# Reconstruct the full Instruct model
5dmx delta-reconstruct qwen2.5-3b-base.safetensors instruct.dmxd qwen2.5-3b-instruct.safetensors
1from safetensors.torch import load_file
2
3weights = load_file("qwen2.5-3b-instruct.safetensors")
4# Load into your framework of choice
This delta requires
Qwen/Qwen2.5-3B as the base checkpoint. The delta is locked to this specific base — reconstruction will fail if a different base is used.
Qwen 2.5 3B is normally distributed as 2 shards on HuggingFace. This delta was created from a merged single-file export. Multi-shard delta support (automatic per-shard matching) is on the
DMX roadmap.
DMX is a structure-aware neural network weight compression format. It achieves 67-87% delta compression by exploiting structural relationships between weight tensors, enabling efficient distribution of model variants as small diffs from a shared base.
Patent Pending. MIT License. (c) 2026 William J. Riley.